Brett Favre's determination to play quarterback this season for the Minnesota Vikings prompted him to undergo arthroscopic surgery to repair his injured passing shoulder recently, according to two sources. However, Favre remains unable to make a commitment because subsequent throwing sessions indicate the shoulder is not yet 100 percent.

While Favre has now clearly demonstrated his interest in coming out of

retirement for a 19th season in the NFL, it seems equally obvious that he will not

do so unless convinced he has recovered fully from the torn biceps tendon

that undermined him last year with the New York Jets.

Favre began considering options to repair the shoulder last month when he sought

advice from acclaimed orthopedic surgeon Dr. James Andrews. Favre and Andrews

discussed surgical and non-surgical options. When cortisone injections and

exercise therapies that included weight lifting failed to release the damaged

tendon naturally, Favre consented to the arthroscopic surgery.

Favre has thrown on a limited basis since the surgery, which occurred last month, but has not felt close to "100 percent" and would not come back unless he makes significant progress, sources said.

Favre's agent, Bus Cook, would not confirm or deny the surgery, saying "That's a confidential client privilege."