Davis (6-6, 355 lbs), who is 33, has played for the Arizona Cardinals and Dallas Cowboys. He signed with the Detroit Lions in November, but did not play in 2011.
Davis is a three time Pro Bowler (2007, 2008, 2009) and was drafted with the second overall selection in the 2001 NFL Draft out of Texas.
ESPN's Mike Sando had this to say on Twitter:
49ers would have 900 to 1,000 pounds of Davises on right side of line if Leonard joined Anthony and Vernon up front.