Minnesota Vikings quarterback Brett Favre (4) waves during warmups before an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings quarterback Brett Favre (4) warms up before an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

San Francisco 49ers tight end Delanie Walker (46) runs for a 24-yard reception against the Minnesota Vikings in the first quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings cornerback Antoine Winfield (26) tackles San Francisco 49ers wide receiver Ted Ginn Jr. (19) in the first quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings quarterback Brett Favre (4) hands off to running back Adrian Peterson in the first quarter of an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

San Francisco 49ers running back Anthony Dixon (33) celebrates after scoring on a 4-yard touchdown run against the Minnesota Vikings in the first quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

San Francisco 49ers quarterback Alex Smith (11) passes against the Minnesota Vikings in the first quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings quarterback Tarvaris Jackson (7) passes against the San Francisco 49ers in the first quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings quarterback Brett Favre (4) stands on the sidelines in the first half of an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings running back Adrian Peterson (28) runs against the San Francisco 49ers in the first quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings running back Toby Gerhart (32) runs against the San Francisco 49ers in the second quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

San Francisco 49ers running back Anthony Dixon (33) is tackled by Minnesota Vikings defensive end Jayme Mitchell (92) and defensive tackle Letroy Guion (98) in the second quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

San Francisco 49ers tight end Nate Byham (82) is hit by Minnesota Vikings safety Tyrell Johnson (25) in the third quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings quarterback Joe Webb (14) is sacked by San Francisco 49ers linebacker Diyral Briggs in the second half of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

San Francisco 49ers quarterback Alex Smith (11) and offensive tackle Joe Staley (74) talk with offensive coordinator Jimmy Raye after an NFL preseason football game against the Minnesota Vikings in San Francisco, Sunday, Aug. 22, 2010. The 49ers won 15-10. (AP Photo/Tony Avelar)

Minnesota Vikings head coach Brad Childress, center, shakes hands with San Francisco 49ers head coach Mike Singletary after an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. The 49ers won 15-10. (AP Photo/Tony Avelar)

San Francisco 49ers head coach Mike Singletary watches from the sidelines during the second half of an NFL preseason football game against the Minnesota Vikings in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings head coach Brad Childress watches from the sidelines in the second half of an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings running back Darius Reynaud (27) is tackled by San Francisco 49ers defensive tackle Derek Walker (78), linebacker Keaton Kristick (45), and defensive tackle Will Tukufatu in the second half of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings tight end Garrett Mills (45) runs past San Francisco 49ers running back Brit Miller (47) in an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings quarterback Joe Webb (14) in an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings quarterback Brett Favre (4) during an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

San Francisco 49ers quarterback Nate Davis (7) in an NFL preseason football game against the Minnesota Vikings in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings quarterback Brett Favre (4) warms up before an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings running back Adrian Peterson (28) in an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings quarterback Brett Favre (4) during an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings quarterback Brett Favre (4) warms up before an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

The San Francisco 49ers Cheerleaders await the 1st quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

A San Francisco 49ers cheerleader performs during the second quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings running back Albert Young (34) during the second quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)

Minnesota Vikings wide receiver Taye Biddle (15) during the second quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings fans react during the first quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

San Francisco 49ers quarterback Alex Smith (11) during the second quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Michael Gotto, center, and other Minnesota Vikings fans watch warmups before an NFL preseason football game between the San Francisco 49ers and the Minnesota Vikings in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings running back Toby Gerhart (32) during the second quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings quarterback Sage Rosenfels (2) in the third quarter of an NFL preseason football game in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

San Francisco 49ers quarterback Alex Smith (11) warms up before an NFL preseason football game against the Minnesota Vikings in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Ben Margot)

Minnesota Vikings head coach Brad Childress watches from the sidelines against in the second half of an NFL preseason football game against the San Francisco 49ers in San Francisco, Sunday, Aug. 22, 2010. (AP Photo/Tony Avelar)