ALAMEDA — San Diego Chargers rookie wide receiver Keenan Allen's NFL career took flight in the fifth game this season, against the Raiders, not far from where he carved out a stellar career at Cal.
He hasn't slowed since that night when he caught six passes for 115 yards and one touchdown in a 27-17 loss to the Raiders at the Coliseum on Oct. 6.
"That was me getting comfortable with the offense, having a feel for the game and Phil (Rivers, quarterback) just trusting me and throwing me passes," Allen said in a conference call with Bay Area media Wednesday.
On Sunday, Allen is expected to play a key role in his team's quest for a victory over the Raiders, a game the Chargers need to win to keep alive their faint playoff hopes.
The first game against the Raiders marked the first time Allen reached the 100-yard mark and scored a touchdown in an NFL game.
"It did a great deal" for my confidence, Allen said. "I was able to build some confidence off of that and Phil was able to have confidence in me, too."
Allen tacked on four more 100-yard games and seven touchdowns in the nine games since he announced his arrival with a breakout performance.
Allen has already set the Chargers record for most receptions by a rookie with 63. He needs only 71 yards in the final two games to break John Jefferson's long-standing franchise mark for most receiving yards (1,001, 1978) by a rookie.
Coincidentally, the Raiders selected linebacker Sio Moore early in the third round, 10 picks ahead of Allen.
Moore has shown promise this season, but he isn't making the kind of impact Allen is for the Chargers.
Raiders coach Dennis Allen said there was some concern about Keenan Allen's injury history before the draft, which prompted the Raiders to target other players.
"I thought he was a very good player. ... I knew he was a very talented player, and he's showing that with the way he's playing," Dennis Allen said.
Keenan Allen said he didn't hear from the Raiders or Chargers before the draft, but he was thrilled by the prospect of going to the Chargers and staying on the West Coast.
Seven receivers went before Allen. It's unclear why, although speculation centered on Allen's less-than-stellar time in the 40-yard dash and his injury history at Cal.
"It was definitely hard watching, especially seeing (some of the) guys picked before me," Allen said. "But it's unfortunate; not only for me but for the other teams that passed on me. I just got to make them pay for it."
Allen suffered a posterior cruciate ligament injury in October that kept him from participating in on-field drills at the NFL pre-draft scouting combine in Indianapolis.
Allen attended the combine, just the same, and he went through the off-field testing and interviews. At some point, his drug test got red-flagged, which resulted in Allen being asked to take another drug test.
"It was all a mistake," Allen said after he was drafted. "The red flag definitely wasn't a failed drug test."
An ESPN report at the time said Allen's test showed suspicious levels of water, a sign he might be attempting to flush his system. Allen's agent, J.T. Johnson, said Allen didn't fail the first test.