CLEMSON -- Clemson head coach Dabo Swinney likes the Tigers' starting units, but one major area of concern this spring is the second-team offensive line.

The unit struggled against the first- and second-team defensive lines in Clemson's scrimmages on Saturday, allowing second-team quarterback Michael Wade little time to throw and little space for tailback Roderick McDowell to run. Offensive coordinator Billy Napier indicated there is a wide gulf between first- and second-team production.

While the starting offensive line made progress last season and loses just one starter, a single injury could expose a soft underbelly.

The one player the Clemson staff is comfortable with on the second unit is junior guard Wilson Norris, though he still needs to improve as a pass blocker.

"We have a lot of freshmen, a lot of young guys," said Norris of the second group. "They are young, they are raw. It takes a long time."

Brandon Thomas, a redshirt freshman, and Phillip Price, a converted tight end, are the reserve tackles and neither has taken an official snap. Backup interior players Kalon Davis, a freshman, and sophomore Matt Sanders are also inexperienced.

Cooper injured

The Tigers are already thin at linebacker and could be without Scotty Cooper for a considerable amount of time. Cooper hurt himself during Friday's practice and was held out of Saturday's scrimmage. Swinney said X-rays will be evaluated early this week. The team is hoping Cooper suffered a groin pull and not a sports hernia, which could require surgery.

NFL sales pitch

While Swinney has talked before about how he believes Kyle Parker has a future in the NFL, he offered perhaps his strongest endorsement to date Monday, following Parker's return to football practice.

"I think he has tremendous NFL ability," Swinney said. "I don't have any doubts he can play on Sunday. I think it would have to be a Brinks truck full of money (for Parker to give up football). At this time next year he'll still have leverage.

"Everyone wants to debate it but I think it would be crying shame if he did not give the NFL a shot."

Extra points

Swinney said redshirting Kourtnei Brown was best for the team and for Brown last year. He said Brown now has a chance to develop into an NFL prospect at defensive end. … Swinney continued to praise linebacker Tig Willard , saying he's "had an excellent spring, is not making many mistakes and is tackling well."