ALAMEDA – After starting cornerback Ron Bartell suffered a broken shoulder blade in the Raiders' season opener, the onus fell on backup Pat Lee to step into a Monday night game against a division opponent and fulfill the "next man up" philosophy of the NFL.

Pressure? It's relative.

Two seasons ago, as a backup for the Green Bay Packers, Lee was thrust into action in the Super Bowl against the Pittsburgh Steelers when Packers cornerbacks Charles Woodson and Sam Shields were injured in the first half.

Lee played 20 snaps and helped keep Steelers quarterback Ben Roethlisberger in check in the Packers' 31-25 victory.

Lee recalled recently that he "played very well. I had a couple tackles. I was looked off a couple times. The ball wasn't really thrown my way at all."

So his sudden change of role in the Raiders' 22-14 loss to the Chargers on Monday felt downright normal.

"That's what backup guys prepare for," Lee said. "I've been playing all my life, and it's not a big deal to go in when somebody else goes down, because that's what we do. That's why we're here."

This week, though, Lee is no longer a "backup guy," a role he couldn't escape in four years in Green Bay. Bartell probably won't need surgery, Raiders coach Dennis Allen said Thursday, but he's expected to miss significant time, leaving Lee in line to start with Shawntae Spencer on Sunday against the Miami Dolphins.

If the Raiders expect to be hindered on defense by replacing the veteran Bartell with the less experienced Lee – who has one career start, when he said the Packers sent out their nickel package for the first play of a game – they aren't letting on.

"We had a whole offseason with him, the same amount of time we had to jell with Ron and the other guys, so I don't think it'll be a chemistry thing with Pat in the game," Spencer said. "He's solid; he's consistent. Works hard – physical, bigger corner – so everything that they asked him to do, he's done."

Defensive coordinator Jason Tarver said the Raiders didn't need to alter their game plan Monday after Bartell left the game in the second quarter.

Lee played 36 of 59 defensive snaps and did not have a big presence on the stat sheet – he was in on two tackles – partly because the Chargers attempted just five passes to their wide receivers after Bartell's exit.

"We expect him to continue to grow, but he did some good things," Tarver said. "Pat's a pro, and we expect that of him. And he expects that of himself."

Lee's time in Green Bay was marred by injuries, including one to his knee that wiped out the 2009 season.

His Super Bowl experience didn't lead to a key role in the Packers' secondary last year – he played mostly on special teams – and Green Bay let him go in free agency after the season.

"I wasn't really too surprised," Lee said. "I just want to play."

In Oakland, Lee was reunited with general manager Reggie McKenzie, who previously worked for the Packers in player development.

Lee started training camp as a third-team cornerback and slowly made a case for more playing time as DeMarcus Van Dyke and Chimdi Chekwa – both since released – fell out of favor.

Spencer said his impression of Lee, 28, is that he's "very low key" but "physical."

"I call him 'Fat Corner,' " Spencer said. "He's a big corner, man. He's 205 (pounds), somewhere in there, and tackles well."

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