Second-year Raiders cornerback DeMarcus Van Dyke appeared headed for a breakout season early in training camp. Then the exhibition games began, and Van Dyke took two big steps backward.

Van Dyke was flagged for pass interference against Dallas in the opener and gave up a couple deep passes Friday night at Arizona. He’ll face a huge test Saturday night against the Lions and their explosive passing attack.

“I’ve got to pick it up,” Van Dyke said. “I’m not satisfied with how I’ve been playing. I haven’t been playing like I thought I was supposed to be. But it’s a process, it’s game by game, preseason games. So hopefully this game I’ll come out and play good.”

Raiders defensive coordinator Jason Tarver said he’s waiting for Van Dyke’s performance in games to match his play in practice.

“DeMarcus, I would really like to see him play like he plays out here, and just play with what we know he can do,” Tarver said. “And he’s heard that from me this week, so that’s what I’d like to see him do. Play like he plays at practice, because he plays pretty good at practice.”

Van Dyke, a third-round draft pick out of Miami last year, said he’s been “pressing too much” during games and needs to relax.

“I’ve just got to go out there and play ball. I’m doing too much thinking, and coach Tarver, he gave me a lot of advice, just telling me to go out there and just play ball. Don’t worry about making mistakes, just play like I was the first two weeks of camp.”

Early in camp, Van Dyke was working with the first team in place of the injured Ron Bartell. Once Bartell’s hamstring healed and he was cleared to practice, Van Dyke returned to second string.

Veteran cornerback Shawntae Spencer said Van Dyke is just going through the typical “growing pains” for a young NFL corner.

“You have to have thick skin. They’re going to catch some balls. You’re going to miss some plays,” Spencer said. “But you got to be strong enough to always compete to the max, stay confident and stay aggressive, because if the opposing team sees you in terms of head hanging, they’re coming right back at you. And it’s going to be for the remainder of the game.

“I told him to look at himself as a starter always. He was playing well when Ron was out with the hamstring, and then Ron came back and it just felt like everything changed. He wasn’t as aggressive.”

Follow Raiders reporter Eric Gilmore on Twitter: @CBSSportsNFLOAK.