It was early in the first quarter last season of the Raiders’ game at San Diego when Chargers starting left tackle Marcus McNeill’s work day ended with an injury.

Chargers backup tackle Brandyn Dombrowski took over, and Oakland's Kamerion Wimbley sacked Philip Rivers four times in a 24-17 Raiders' victory.

The Raiders hope they can get to Rivers again on Monday night when they face San Diego in their season-opener.

Dombrowski is no longer a Charger. And Wimbley, who doubled as an outside linebacker and nickel defensive end the past two seasons, now plays for Tennessee. But a back injury has sidelined Chargers starting left tackle Jared Gaither, and backup Mike Harris, an undrafted rookie from UCLA, will start Monday night in his NFL debut.

Raiders starting defensive right end Matt Shaughnessy will line up against Harris.

“He looked pretty good on film,” Shaughnessy said of Harris. “Obviously they’re very happy with what he’s doing, so he’s playing.

“You can’t take anybody lightly. You got to treat everybody the same and prepare the same way and that’s what we’re doing this week.”

Wimbley used his speed and quickness to consistently beat Dombrowski off the edge. Shaughnessy relies more on power and is known most for his ability to stop the run.

“I’m not Kam,” Shaughnessy said. “We’re totally different people.”

Maybe so.

But Shaughnessy’s combination of power and relentless effort will present a stiff test for a rookie forced into the starting lineup in his first NFL game.

When asked what Shaughnessy does well, Raiders defensive coordinator Jason Tarver cracked a smile.

“Go straight ahead and run into things,” Tarver said. “Matt loves football, and when you aim him somewhere, he goes and hits where he’s aimed. He does a nice job of using his hands and playing the physical part of the game. … We’re excited that he’s healthy. I can’t wait to watch him play.”

Shaughnessy suffered a season-ending shoulder injury last year in the third week against the Jets. He underwent surgery and wasn’t cleared for full practice until late in the offseason. He said he can’t wait for Monday night’s game for reasons that have nothing to do with facing a rookie tackle.

“It’s already been a year that I haven’t been able to play and do anything, so just being out on the field, I’m very excited,” Shaughnessy said.

It’s likely that Tarver will send a number of different pass rushers at Harris and turn up the heat with a variety of blitzes and stunts. But he said he can’t “get too focused on that one spot” or Chargers coach Norv Turner will make the Raiders pay by attacking a weakness that develops.

“We know (Harris) is out there. They know he’s out there,” said Tarver, who was a 49ers assistant coach when Turner was San Francisco’s offensive coordinator in 2006. “It’s a chess match to see how much they help him, how the scheme goes around him and what players we can match on him.”

Turner said Harris is “a very mature guy” for a rookie and has far exceeded expectations.

“He impressed us from the beginning,” Turner said. “You’d like him to be in a position where he’s learning and waiting his turn, but he’s doing a good job preparing to play.”

Follow Raiders reporter Eric Gilmore on Twitter: @CBSSportsNFLOAK.