But Polk will have to sub for Merriman for the next four weeks, holding down his outside linebacker spot while Merriman serves his suspension for a positive drug test.
"He's been waiting for this moment for his whole life," veteran linebacker Randall Godfrey said. "I hate that it is this late in his career, but it's good for him."
This is Polk's sixth season, but Sunday will mark his first NFL start. He has made his mark with the Chargers as a special teams dynamo, when he can stay healthy.
In offseason workouts in 2005, he tore his Achilles tendon and landed on injured reserve. The year before that he suffered a shoulder injury that restricted him to one game.
Now all eyes are on him as he fills in for one of the NFL's top defensive players on one of the NFL's top defensive units.
"He's a good football player," coach Marty Schottenheimer said. "I think he will do fine. He understands what he is doing. He is a savvy veteran."
Polk was the team's co-special teams player of the year in 2003. And he'll still be asked to contribute on special teams Sunday, despite his newfound status as a starter.
"I'm just going to try and do my job and not try to do too much," Polk said. "Just do my job and I'm sure everything else will work out like it is supposed to."
Kellen Winslow sounds eager about having a big game Sunday in San Diego. For Winslow, it's personal.
He will be returning to the town where he grew up and where his Hall of Fame father played professionally.
And he will face Antonio Gates, one of the other top tight ends in the league.
"I look at it like it's a heavyweight match," Winslow said. "It's me vs. Gates."
One he takes personally.
"I'm trying to be the best," he said. "I said I was the best. I am the best. And I'm going to prove it on Sunday."
Winslow leads all NFL tight ends with 40 catches, but he watched from the sidelines the past two years while Gates caught 81 and 89 passes for 964 and 1,101 yards.
Winslow does not back down. In training camp he said he would never be 100 percent after hurting his knee in a motorcycle accident, but 90 percent of him is better than every tight end in the league.
"That's not being arrogant," he said. "I am. I know what I can do. They know what I can do. The defensive coordinator knows what I can do."