Kansas City quarterback Trent Green is out of hospital after he was knocked unconscious in the Chiefs' 23-19 NFL season-opening loss to Cincinnati.
Green, a two-time Pro Bowler, suffered what team officials said was a "very severe concussion" after being hit by Bengals defensive end Robert Geathers.
He will be sidelined indefinitely but Chiefs coach Herm Edwards said the 36-year-old veteran is keen to return.
Edwards said. "If it was up to Trent, he would show up tomorrow."
But Edwards said the Chiefs will not rush Green back into action.
"We've got to make sure Trent is OK, that's the important thing," he said.
Green was out cold for several minutes after the third-quarter incident in Sunday's game.
"I know I didn't hit him head-to-head," Geathers said. "I think it was my shoulder pad that hit him in his chest.
"But it was hard watching him down on the ground."