Top photos from Keenan Allen's sensational, yet injury shortered, season.
The Chargers annual Salute to Service NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
The Chargers annual Salute to Service NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Sean McGrath and a U.S. marine talk at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Sean McGrath and a U.S. marine talk at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston shakes hands with a U.S. marine at at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston shakes hands with a U.S. marine at at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Denzel Perryman warms up before an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Denzel Perryman warms up before an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Sean McGrath shakes hands with a U.S. marine at at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Sean McGrath shakes hands with a U.S. marine at at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Sean McGrath plays against a U.S. marine in Madden 17 at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Sean McGrath plays against a U.S. marine in Madden 17 at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Anthony Lynn takes a photo with U.S. marines at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Anthony Lynn takes a photo with U.S. marines at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Chargers players, Charger girls and U.S. marines pose for a picture at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Chargers players, Charger girls and U.S. marines pose for a picture at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Philip Rivers arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Philip Rivers arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Chargers players, Charger girls and U.S. marines pose for a picture at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Chargers players, Charger girls and U.S. marines pose for a picture at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston watches a U.S. marine play Madden 17 at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston watches a U.S. marine play Madden 17 at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston plays against a U.S. marine in Madden 17 at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston plays against a U.S. marine in Madden 17 at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Anthony Lynn takes a photo with U.S. marines at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Anthony Lynn takes a photo with U.S. marines at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Trevor Williams arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Trevor Williams arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Anthony Lynn and a U.S. marine laugh at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Anthony Lynn and a U.S. marine laugh at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Sean McGrath warms up before an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Sean McGrath warms up before an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Corey Liuget arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Corey Liuget arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Tre Boston shakes hands with a U.S. marine at at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston shakes hands with a U.S. marine at at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Trevor Williams shakes hands with a U.S. marine at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Trevor Williams shakes hands with a U.S. marine at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston reacts to a game of Madden 17 during Pros vs. GI Joes on Friday, Nov. 17, 2017.
Tre Boston reacts to a game of Madden 17 during Pros vs. GI Joes on Friday, Nov. 17, 2017.
Chargers players, Charger girls and U.S. marines pose for a picture at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Chargers players, Charger girls and U.S. marines pose for a picture at Pros vs. GI Joes on Friday, Nov. 17, 2017.
San Diego Chargers wide receiver Keenan Allen reacts after a reception against the Detroit Lions during the first half of an NFL football game Sunday, Sept. 13, 2015, in San Diego. (AP Photo/Alex Gallardo)
The Chargers annual Salute to Service NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
The Chargers annual Salute to Service NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
The Chargers annual Salute to Service NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
The Chargers annual Salute to Service NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Damion Square arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Damion Square arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Trevor Williams shakes hands with a U.S. marine at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Trevor Williams shakes hands with a U.S. marine at Pros vs. GI Joes on Friday, Nov. 17, 2017.
Chargers players and Charger girls join U.S. marines for Pros vs. GI Joes on Friday, Nov. 17, 2017.
Chargers players and Charger girls join U.S. marines for Pros vs. GI Joes on Friday, Nov. 17, 2017.
Korey Toomer arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Korey Toomer arrives at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Pros vs. GI Joes on Friday, Nov. 17, 2017.
Pros vs. GI Joes on Friday, Nov. 17, 2017.
Cardale Jones prepares for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Cardale Jones prepares for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Jatavis Brown, Travis Benjamin, and Jahleel Addae arrive at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Jatavis Brown, Travis Benjamin, and Jahleel Addae arrive at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Casey Hayward, Trevor Williams, and Desmond King arrive at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Casey Hayward, Trevor Williams, and Desmond King arrive at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Sean Culkin and Derek Watt arrive at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Sean Culkin and Derek Watt arrive at StubHub Center for an NFL football game against the Buffalo Bills Sunday, Nov. 19, 2017, in Carson, Calif.
Keenan Allen enters his fourth NFL season at just 24 years old.
On Friday, the Chargers made sure he will spend the foreseeable future donning the lightning bolt.
The Bolts agreed to terms on a four-year extension with the star wide receiver, locking him up through 2020.
Since being selected with the 76th overall pick in the third round of the 2013 draft, Allen has emerged as one of the NFL's top playmakers. The 6-2, 211-pound wideout has caught 215 passes for 2,554 yards and 16 touchdowns in 37 career games.
Allen elevated his game to new heights in 2015, catching 67 passes for 725 yards and four touchdowns before his season was cut short by a kidney injury in Week 8. Nonetheless, KA13 was voted the Chargers Offensive Player of the Year. His 67 catches through eight games were the third most in NFL history, and he was on pace for a 143 catch season, which would have shattered LaDainian Tomlinson's team record of 100 set in 2003. Allen also ranked third in the league in receiving yards at the time of his injury.
It was clear Allen was in for a special season from the first game of the year when he tied Kellen Winslow's single-game franchise record with 15 receptions against the Detroit Lions. Just two weeks later, he caught 12 passes against the Minnesota Vikings before a 14-catch effort Week 6 at Lambeau Field against the Green Bay Packers despite missing the entire fourth quarter. In the process, number 13 became the first player in NFL history with at least 12 catches in his team's first six games of the season.
Allen burst onto the scene with a dynamic rookie season that earned him Pepsi Next Rookie of the Year honors. He filled in for an injured Malcom Floyd midway through Week 2 and never looked back, totaling 71 receptions for 1,046 yards and eight touchdowns. Allen recorded back to back 100-yard games on two occasions, becoming the first Chargers rookie to do so since 1960. KA13 also became only the fifth rookie since 2000 to surpass 1,000 yards in a season.
His rookie campaign was highlighted by a two-game stretch over the course of five days late in the year against the New York Giants and Denver Broncos. He caught four touchdowns to spark the Bolts on a memorable run to the playoffs, including a leaping score at Mile High Stadium where he hurdled his defender and fought his way into the end zone. His five touchdown catches in a three game span were the most by a Chargers wide receiver since 1996.
In the postseason, Allen continued his torrid rookie campaign by catching eight passes for 163 yards and two touchdowns in two games. Despite falling to the Broncos in the divisional round, he totaled 142 yards and two touchdowns on six catches, which were good for the second most receiving yards in a playoff game in team history. Moreover, it marked the second most for a rookie in NFL history after Philadelphia's Keith Jackson. Allen also authored the Bolts' first two-touchdown postseason game since Winslow in 1983, and he became the first NFL rookie to do so since New England's Julian Edelman in 2010.
In 2014, Allen set a career-high with 77 catches for 783 yards and four touchdowns. However, his sophomore season was cut short when he injured his clavicle Week 15 against the Denver Broncos. As a result, he missed the team's final two games as they fell short of the postseason.
Despite all his accomplishments, Allen remains driven to reach new heights in the future with Philip Rivers at the helm.
"We've built up a trust over the years," he said earlier this offseason. "His confidence in me helps me play better. It makes me not think as much and lets me just play my game. When I get in my groove, I do feel like nobody can stop me. And that's because I know all I have to do is get to my spot and Philip will get me the ball. I think he's helped me become a more disciplined player."
