NAPA – Chimdi Chekwa said he and his fellow young Raiders cornerbacks have bestowed a nickname on veteran Shawntae Spencer this summer: "Unc."

Indeed, the 30-year-old Spencer has seniority over just about all of the Raiders' defensive backs in training camp both in years and experience, having played the past eight seasons for the 49ers.

Spencer started all 32 games for the 49ers in 2009 and 2010 but slid down the depth chart last year while battling injuries. Five days after the 49ers released him in March, the Raiders added him to their then-depleted secondary, offering a change of scenery.

"I think it was needed," Spencer said after the Raiders practiced in pads for the first time Wednesday. "I think the direction San Francisco was going was obviously in a different direction, and I think it was something that was positive for both sides, for them and me. I'm looking forward to just getting a fresh start."

During the offseason, the Raiders jettisoned both their starting cornerbacks from last year, Stanford Routt and Chris Johnson, and signed Spencer and Ron Bartell. Both veterans, who share a birthday, have spent most of the offseason with the first-team defense, though Bartell has been held out of training camp with a hamstring injury.

The Raiders are phasing out the reliance on man-to-man coverage favored by Al Davis under a new regime that includes coordinator Jason Tarver, whom Spencer already knows. Tarver was a defensive assistant for much of Spencer's time with the 49ers.

"It's the same defense I've been in my whole career with Jason Tarver," Spencer said. "There's a few things that are (new), things from (coach Dennis Allen), but for the most part the terminology and the scheme is pretty much what I've been in my whole career."

The familiarity has helped ease Spencer's transition into his new secondary. Returning safety Tyvon Branch said neither Spencer, who has 11 career interceptions and 53 passes defended, nor Bartell has required much direction.

"They're older guys; they know the game," Branch said. "It's not as much us trying to line them up. They're pros. They get in the playbooks and know what they're doing."

As veterans, part of their job is to mentor second-year cornerbacks DeMarcus Van Dyke and Chekwa, Allen said. Both have impressed Spencer, who said it isn't difficult balancing that responsibility with battling for a starting job.

It is similar, Spencer said, to the role he assumed in San Francisco with younger corners like Tarell Brown, who had four interceptions for the 49ers last year in his first season as a full-time starter.

"We have a great coaching staff for helping them improve their game and things like that," Spencer said. "Me, I'm just there for support, any questions they might want to ask me about on the field, off the field, things like that.

"I guess in the past they didn't have good relationships with the older corners and things like that," he said. "We always (say), 'DVD those guys, you are starting corners. If we go down, you're in there right now. Conduct yourself as a starting corner.' "

Their guidance has benefited the second-year players, Chekwa said, particularly when it comes to "the technique side" of playing corner.

"We came in last year with no offseason workouts, so we just came in after the lockout and everything was going so fast we didn't get to learn the technique side of it," Chekwa said. "It's good to have that mentorship."

With Bartell sidelined this week, Van Dyke has taken the first-team snaps with Spencer and made several standout plays, including breaking up a deep pass from Carson Palmer to Darrius Heyward-Bey in team drills Wednesday. Spencer has taken note.

"Very quick corner, very fast corner, very long corner, as well," Spencer said of Van Dyke. "Great instincts and things like that. I'm very impressed with the young man's game."

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