Trent Dilfer faces a radical transition this week, jumping back into the starting quarterback arena after two years on the sideline as a veritable Yoda in shoulder pads.

As an added plot boost, Dilfer’s shift from mentoring Alex Smith to filling his spot comes Sunday against the same Baltimore Ravens team – and, most specifically, Coach Brian Billick – that dumped him after they won the Super Bowl in 2001.

But the veteran quarterback, who fared poorly in relief last Sunday after Smith’s shoulder was separated on the opening drive, has bigger things to focus on than revenge.

“There’s 52 guys in that room and an entire community counting on me to play the best football of my life on Sunday,” Dilfer said. “That’s a big enough responsibility in itself. I can’t be worrying about who we’re playing or what the circumstance are. It will just take away from my ability to do what I need to.”

Dilfer attempted to bury the hatchet with Billick this week, but admitted the memories of becoming the first Super Bowl-winning quarterback not to be invited back still sting.

Boosted by the Ravens’ tremendous defense, Dilfer went 11-1 as Baltimore’s starter in 2000 – culminating in the Ravens’ only Super Bowl title.

Soon thereafter, seeking more explosiveness than steadiness, Billick cut Dilfer and went with Elvis Grbac. The decision left Dilfer, 35, embittered and continues to rankle him.

“I certainly understand it,” Billick said in a conference call. “It was an organizational decision across the board and we did what we did.”

Eight months ago, Dilfer told the Baltimore Sun that Billick “grossly misunderstood the talent of that football team, myself specifically. I totally agree with so many things he did. But to this day, I am so sad I didn’t have the chance to face the challenge of repeating.”

Dilfer has softened his tone. Though he described himself as still heartbroken over the circumstances of his Baltimore departure, Dilfer said he planned to seek out Billick before Sunday’s game. He said he wants to tell him face to face that he regrets the harshness of his remarks, as well as his refusal to speak with his former coach after Billick had sought to repair their relationship.

“I’m making a public apology but I want to make sure he knows that I’ve let that go,” Dilfer said. “It’s not my place to question that decision any more. I can disagree with it but I don’t want to hold the bitterness. He’s been the man and I’ve been the child and it’s about time I fix that.”

In extending an olive branch, Dilfer also hopes to help himself and the 49ers in making his first start since suffering a season-ending knee injury while with Cleveland in November of 2005.

“My wife had some great advice: ‘You’ve got to worry about you. You can’t worry about the other stuff. You’ve got to play better than you did last week,’ and she’s absolutely right,” said Dilfer, who was 12 of 33 for 128 yards, was sacked five times and intercepted twice.

One thing he needs to do quickly is make the transition from a passive role as Smith’s mentor and confidant to the on-field focal point of the offense.

“I’m never offended by the mentor role. I understand and I embrace it,” Dilfer said. “Hopefully, I taught Alex some lessons last week in what not to do in close games.”

Coach Mike Nolan said there were always two principal aspects to Dilfer’s job: showing Smith the ropes and taking the reins if the need arose.

“When he has the opportunity to play, whether it be because of injury in this case or any other reason, he’s expected to perform at a high level,” said Nolan, adding that the results didn’t bear that out last Sunday.

“I thought he tried to do too much instead of letting the game come to him,” Nolan said. “Certainly, he’ll try to correct those things against Baltimore.”

Dilfer said there’s nothing wrong with him or the rest of the offense that can’t be fixed with some practice and repetition. But he described playing against the Ravens’ defense as “an incredible challenge.”

“You have to be very precise in what you do,” Dilfer said. “You have to be very instinctive and you can’t think too much.”