SAN FRANCISCO (AP) _ Once the San Francisco 49ers' season is over, Steve Young can expect a serious conversation with agent Leigh Steinberg about the quarterback's repeated head injuries.

Young has sustained two concussions in the past three games and six serious concussions over the course of his professional career. He won't play in Sunday's game against the Baltimore Ravens.

``This is an issue that is much more serious than the other injuries a player may suffer,'' Steinberg said Friday.

Steinberg said that during the offseason he and Young would discuss several options, including the possibility of using a special helmet. He said talk about Young's possible retirement was premature.

``Steve is so focused on the Super Bowl that now is not a good time for a discussion,'' the agent said.

Young sustained the latest concussion early in last Sunday's 20-17 overtime loss to the Dallas Cowboys. Elvis Grbac will start in place of Young on Sunday when the 49ers (7-3) play host to Baltimore (3-7). Young expects to start Nov. 24 at Washington.

Jeff Brohm will back up Grbac on Sunday, and the 49ers signed 1992 Heisman Trophy winner Gino Torretta on Friday as the inactive, or emergency, quarterback just in case.

Young could not immediately be reached for comment on Friday but earlier this week said he felt fine.

``I talked to the neurologist and he saw how good I felt. I think he wanted to say, `Go ahead and play,' but just felt because of two in 14 days it would be wise to take time off,'' Young said.

Last year, Steinberg organized a seminar for athletes concerning head injuries. Young and fellow Steinberg clients Troy Aikman of the Dallas Cowboys and Warren Moon of the Minnesota Vikings were among those who attended.

Steinberg noted that research indicates concussions lead to an ``increased risk of Parkinson's disease, Alzheimer's and senility.''

``Brain function is the last frontier of medical research,'' he said. ``No doctor can say how many concussions is too many.''

Steinberg said it is difficult to determine exactly how many concussions Young has had during his career because the quarterback tends to play through what he calls `mini-concussions.''

``An official concussion is one in which he is carted off the field,'' Steinberg said. ``A mini-concussion is one in which he's momentarily dazed or stunned but he continues to play.''