Titans QB Steve McNair will undergo back surgery today to repair a ruptured disk and will be out of the lineup for six weeks. Veteran Neil O'Donnell, signed as a free agent just before training camp, will start today for Tennessee (1-0) against the visiting Browns (0-1).

McNair flew yesterday to Los Angeles, where Robert Watkins will perform the procedure at University Hospital at the University of Southern California. McNair sat out Thursday's practice when he woke up with back spasms and stiffness. He returned to practice Friday when the injury apparently occurred.

SANDERS UPDATE: NFL Commissioner Paul Tagliabue is not expected to get involved in talks to get RB Barry Sanders to end his retirement now that his dispute with the Lions is headed for arbitration, the player's agent said yesterday.

David Ware said he had spoken to Tagliabue before the Lions filed papers to have a portion of Sanders's signing bonus returned.

Lamont Smith, Sanders's other agent, asked Tagliabue in a letter Monday to help settle the grievance, aimed at recouping $5.6 million of the signing bonus the Lions contend Sanders owes them. Ware said since Tagliabue does not get involved in these kinds of disputes, an arbitrator will be appointed.