"I'm their leader and I want to be on the field," he said.
It appeared Kitna's day was over when he stood on the sideline with his helmet off for about two quarters, only to return midway through the fourth period, drawing a roar from the crowd at Ford Field.
He was hit hard several times by the Vikings, and Kenechi Udeze delivered one of the blows by driving Kitna's face into the ground.
"I got knocked to the turf and it knocked me woozy for a while," Kitna said. "I've had concussions before, but this was like nothing I experienced before. In the first 20 minutes after, I was pretty foggy."
After Kitna's last drive in the second quarter, which ended with a touchdown pass to Roy Williams, he went to the bench. A flashlight was shined toward his eyes and a wet towel was draped over his head while trainer Al Bellamy evaluated him.
Kitna finished 22-of-33 for 245 yards with a TD and interception.
Until J.T. O'Sullivan threw five passes on his first possession in place of Kitna, his experience in the league consisted of kneeling down twice to seal a win for Green Bay in 2004.
He was 13-of-23 for 148 yards with a score, two interceptions and a fumble.
O'Sullivan, drafted in the sixth round in 2002 by New Orleans, has been on a handful of rosters in the league and led the Frankfort Galaxy to NFL Europa's World Bowl earlier this year and in 2004.
Chicago cut him just before training camp, and the Lions quickly signed him.
The former California-Davis standout went from possibly being released again to being the No. 2 quarterback because second-round pick Drew Stanton went on injured reserve with a knee injury and Dan Orlovsky had a toe injury in the second preseason game.
Copyright 2007 by The Associated Press
