Nnamdi Asomugha's two years in Philadelphia were an unquestioned disappointment, and the Eagles released the former high-priced free agent last month even though they're on the hook to pay him $4 million. Asomugha signed with the 49ers, where he has a chance to resurrect his career in the Bay Area.

There are legitimate questions about whether Asomugha will ever be the type of player he was with the Raiders, when his production and reputation as one of the NFL's finest cornerback prompted the Eagles to offer a five-year, $60 million contract.

Asomugha's new deal, however, comes with no guaranteed money, meaning he will need to prove his worth by earning incentives included in the deal.

"It was a myriad of reasons," Asomugha said to Bay Area-reporters about why he struggled with the Eagles. "We could sit down and talk for a couple of hours. The bottom line is I didn't get it done out there. It just didn't work out. I have a chance to step back on the field and do it again, do it over."

One reason often attributed for his struggles in Philadelphia was the scheme, which did not have the same man-to-man principles that he played in Oakland. Asomugha said he placed an emphasis on the scheme during this free agency period.

"I think 49ers have a good mix, what (defensive coordinator) Vic Fangio does I think has been awesome, over the last two years from what I've seen," Asomugha said. "Having a chance to do it again, definitely had to make sure the scheme was something I liked and I was able to find San Francisco with a scheme that I thought was really impressive."

He also noted the difference of the Bay Area and Philadelphia. Asomugha played at Cal and Oakland, and grew up in Los Angeles. Philadelphia was a major difference. He also has a prior relationship with 49ers coach Jim Harbaugh.

"I think the contrast is I didn't really know anyone [in Philadelphia], and it was a new area for me," Asomugha said. "Those were probably the biggest differences. And then out here, there is that familiarity with the area and with players and coaches."

What's clear is that Asomugha has much to prove. His time in Philadelphia is the last memory, but he can change the lasting reputation depending upon how he plays with the 49ers.

"I've never gone into a season thinking I didn't have something to prove," Asomugha said. "Always had a chip. The chip might be a little bigger now, but it's always been there.