McCown spent last year with the Detroit Lions but did not throw a pass. over his first four years in Arizona, the Sam Houston State alumnus tossed 25 touchdowns to 29 interceptions.
Noted for having a strong arm - he completed 65 passes over 20 yards and 11 over 40 yards - McCown also has mobility in the pocket. He has rushed for 429 yards on 94 attempts.
The rumors first circulated during the owners' meetings in Arizona and have been confirmed by a source familiar with negotations.
The Lions are listening to offers, although they may not want to trade McCown, especially to Oakland.
"If they trade McCown to Oakland, the Raiders presumably can take wide receiver Calvin Johnson -- whom Detroit (spearheaded by offensive coordinator Mike Martz) likely has atop their draft board," said the source. "But if they don't trade McCown to Oakland, the Raiders presumably will take quarterback JaMarcus Russell, and the Lions draft position will remain the same."