Steve Young's concussion is more serious than originally thought and as much as the 49ers quarterback wants to play, there's no telling when or if his doctors will let him. So far, they've been reluctant to clear him to play and Coach Steve Mariucci said yesterday that Young probably will miss his third straight game this week.

"Evidently, they don't feel this is the appropriate time to let him start banging around," Mariucci said. "I know we're all being very conservative and they are too because of the frequency of the concussions. They're taking their time. They're trying to make sure that when they say yes, it's a go."

Mariucci reiterated that even if Young eventually receives medical clearance, the team may continue to hold him out for an indefinite period just to make sure he's all right.

* SHARPE OUT AT LEAST 8 WEEKS: Broncos Pro Bowl TE Shannon Sharpe will be sidelined for at least eight weeks with a broken left collarbone, just a week after the team lost league MVP Terrell Davis for the season with torn knee ligaments.

"I'd say eight weeks is pretty optimistic," Broncos Coach Mike Shanahan said. "Especially at that position where you're asked to catch and block and do a number of different things. I'd say it would be closer to nine or 10 weeks." . . .

Falcons LB Keith Brooking will be out at least three weeks with a knee injury, while Pro Bowl LB Jessie Tuggle is doubtful for Sunday's game against the Rams because of a sore thigh.