He had his baptism by fire the first time he stepped on an NFL field."At the start of the preseason," DeMarcus Van Dyke mused during last month's OTA's, "I played against Larry Fitzgerald and I had a bad experience. But after that, I tried to make more plays, and it helped my confidence a lot."And as such, Van Dyke is the most intriguing defensive back on the Raiders roster as the team prepares to report to Napa for training camp on July 28. The second-year cornerback was the quintessential Al Davis draft pick -- speed to burn, somewhat overvalued as a third-round draft pick.But the new regime sees something in the lithe Van Dyke, and Van Dyke, who is starting to fill out physically, sees something in himself. Yes, the guy who blazed to a 4.25-second 40-time at the Combine will push veteran signees Shawntae Spencer and Ronald Bartell for playing time and maybe even for a starting job.Intrigued yet?"Next year, I just need to make more plays on the ball," Van Dyke said. "I had a bunch of chances to make interceptions that I dropped. And sometimes I kept my head on the receiver and didnt look for the ball. Thats why at these OTAs I am trying to find the ball and make plays and hopefully help out next year."Rookie coach Dennis Allen, who cut his teeth coaching up defensive backs, agreed."You've got to practice to get better," Allen said.As a rookie last season, Van Dyke had a Raiders cornerback-best burn rate of 43.8, per Stats Inc., giving up 14 receptions on 32 targets for 167 yards and a touchdown while being credited with four passes defensed. By comparison, the departed Stanford Routt had a burn rate of 47.4 while Matt Giordano's was 42.5 and Mike Mitchell's was 34.6.Both Spencer and Bartell had injury-shorted seasons in 2011 and their burn rates were 44.4 (four of nine) and 66.7 (two of three), respectively.Van Dyke, now listed at 180 pounds, has found guidance from the two thus far."Its the small things, like looking at the splits of the receivers and watching a lot of tendencies on film," he said. "I really appreciate those two guys helping me out as leaders this year.Especially with a new regime and a new scheme."I am loving it," Van Dyke said. "Its vision defense -- you see a lot of stuff and were going to make a lot of plays next year."A year ago, the lockout wiped out any offseason activities, putting Van Dyke and his fellow rookies further behind an eight ball that the likes of Fitzgerald enjoyed shooting at the newbies."Without the OTAs and the minicamps, it really set a lot of the guys back," Van Dyke said. "But this year, its helped and I cant wait to see how I play."He's not the only one.