After enduring a 2011 season filled with on-field discipline issues and an offseason filled with off-field legal problems, Jim Schwartz stressed the importance of his players maintaining composure at the start of Lions’ camp.

If Thursday’s practice is any indication, his players are getting the message.

Late in the workout, there was the first real scuffle between players in what has been a relatively calm camp when C Dominic Raiola appeared to shove rookie LB Tahir Whitehead following a drill. Rather than engaging with Delmas, however, Whitehead simply retreated to the defensive huddle -- avoiding what surely would have been a retaliation penalty in game action.

“I think that the players showed some restraint,” Schwartz said. “The biggest thing is not letting those things get ahold of you, and I thought Tahir [Whitehead] did a very good job in that situation.”

If Lions’ players can follow Whitehead’s example, it will help them avoid the lapses in discipline that cost them at key points last year.

Wendling and Bentley set to start preseason opener: Coach Jim Schwartz didn’t name a starting lineup for the preseason opener vs. Cleveland, but that didn’t stop S John Wendling and CB Bill Bentley from confirming that they expect to be part of the first-team unit. Wendling has filled in well in relief of the injured Louis Delmas, and Jim Schwartz said the veteran could play an increased role in 2012. [Wendling’s role isn’t] just special teams with spot play,” Schwartz said. “He’s doing a good job playing the safety position.”

Bentley’s rise from untested rookie to presumptive starter has been one of the unexpected developments of camp. He made another interception Thursday and has been one of Detroit’s most consistent defensive performers. If Bentley can carry his solid practice efforts over to game action, he’ll take a significant step towards cementing a starting job.

Avril practicing well, may sit vs. Browns: Since ending his week-long holdout Sunday, DE Cliff Avril is looking more settled with each workout. The quickness that helped him make a team-best 11 sacks in 2011 didn’t diminish during his absence from team activities, and he would have made his first sack of the season Thursday if contact in drills was allowed.

Although Avril looks just as sharp as he did when the 2011 season ended, he says he doesn't expect to play in Detroit’s preseason opener Friday. "If I'm not ready, there's no point in going out there,” he said. “I haven't practiced in pads yet, so I don't know if that would be a good idea." If Avril doesn’t play, Willie Young will likely take first-team reps in his place.

Follow Lions reporter John Kreger on Twitter @CBSSportsNFLDET and @johnkreger.