NAPA, Calif. — Like a new parent marking off firsts — word, step, peaceful night — Raiders defensive coordinator Jason Tarver said he's excited about Saturday's game against Detroit and the way it figures to test his fledgling defense.

NAPA, Calif. — Like a new parent marking off firsts — word, step, peaceful night — Raiders defensive coordinator Jason Tarver said he's excited about Saturday's game against Detroit and the way it figures to test his fledgling defense.

Detroit's offense ranked in the top five in the league last year in yards, passing yards and points per game. More interesting to Tarver is that the Lions can "change the tempo of the game on offense" in ways that the Raiders haven't seen yet in the preseason.

"They can put bigger guys on and run and take shots to the big receivers and their other guys who are fast," Trave said, "or they can put three wide receiver personnel groups or flex (a tight end) and different guys out and change the pace of the game.

"I'm most interested in our process and how we handle those situations, because we haven't gotten a lot of that yet."

Tarver said he has been pleased with the progress of the defense. The first-team defense played a half and gave up two touchdowns in Friday's 31-27 loss at Arizona, but both scores came on drives that started in the Raiders' territory. Overall, the Cardinals netted 42 yards on 22 plays in the first half.

"Applying the rules we've been doing pretty well, and learning how to work together we've been doing pretty well," Tarver said. "I like that the last game we got in stressful situations early, because I want to see how we respond."

One player Tarver said would be "good to see" Saturday is rookie defensive end Jack Crawford, who hasn't played in either preseason game. Crawford, a fifth-round draft pick, appeared to be a candidate to bolster the Raiders' pass rush early in camp but has been hampered by a foot injury. He has practiced this week.

Depth in the secondary also is still sorting itself out, Tarver said.

At cornerback, Chimdi Chekwa and DeMarcus Van Dyke have been the primary backups, but Van Dyke has had an up-and-down camp. Veteran Pat Lee is back after missing the Arizona game for the birth of his child and Bryan McCann is also a backup returner on punts and kickoffs.

Offensive line settling

Aside from center, where Alex Parsons continues to fill in for Stefen Wisniewski (calf), the starting offensive line seems set, offensive coordinator Greg Knapp acknowledged Wednesday.

Tackle Jared Veldheer and guard Cooper Carlisle on the left side and tackle Khalif Barnes and guard Mike Brisiel on the right have been constant since early offseason workouts.

"They've done a good job," Knapp said. "I'm feeling comfortable with both guards and tackles. They're communicating well, they're seeing the game from the zone-blocking scheme and the play-pass stuff very well. So yeah, they're doing real well together."

Coach Dennis Allen said Wednesday that Wisniewski likely won't play against the Lions. Knapp said he feels comfortable with Parsons at center in part because the position has been an open competition since the spring, and Parsons has taken more reps.

Odds and ends

Defensive tackle Richard Seymour hasn't practiced this week, but Allen said it isn't cause for alarm. Seymour, going into his 12th NFL season, "pushed real hard early in camp," so the Raiders are making sure they don't overtax him, Allen said.

"It's not an injury," Allen said. "We have to get him enough work to get him ready to play, but yet have him ready to play so we can have him for a full 16 games this year."

Backup quarterback Matt Leinart will be a game-time decision against Detroit. Allen said Leinart is "fine to play" after getting two stitches to close a cut on his right index finger resulting from a late hit by Cardinals defensive tackle Ricky Lumpkin.