The drives he extended led to a touchdown and field goal, respectively.

Tight end Antonio Gates shook his head in the locker room this week when discussing Allen's growth.

A knee injury sidelined Allen for the end of his 2012 season at California. He was reportedly clocked at 4.71 seconds in his fastest pro-day attempt at the 40-yard dash, which didn't help his fall to the third round.

"I knew he was good, but I've never seen this," Gates said. "I didn't think it would evolve this fast. He is making plays in the game, and I'm like, 'Wow.' ...

"You don't really expect it. They talk about his speed and this and that. The boy can play football, and he can get open. All that stuff about speed. If you can play and get open, that's what wins games for you. That's what makes plays for you. You can get a dog to run and jump. You know what I mean? That's what this league has underestimated."

Chargers wide receivers coach Fred Graves rode Allen when he was struggling.

Despite Allen's progress, the push for more hasn't stopped.

Veterans see the potential in the receiver. They encourage him to keep going, remind him that success in the NFL isn't about stringing games together. It's about the long haul, about season after season.

In a short span, quarterback Philip Rivers has come to trust Allen on the field. He can have a conversation about what to do during the game should a scenario arise, Allen will say he understands, and then during the game, sure enough, he'll prove it.

"I say this: It's been impressive what he's done," Rivers said, "but he can be even better."

In Week 6, Allen played the first Monday Night Football game of his career. He caught a career-high nine of 12 passes for 107 yards and a 22-yard touchdown. The performance earned him publicity and Pepsi Next Rookie of the Week honors.

Coach Mike McCoy saw Allen's father at one of the Chargers' games this season.