Dallas Cowboys cornerback Alan Ball returns a blocked field goal for a touchdown during the first half of an NFL preseason football game against the Minnesota Vikings, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Jim Mone)

Minnesota Vikings wide receiver Bernard Berrian catches a touchdown pass in front of Dallas Cowboys safety Gerald Sensabaugh (43) during the first quarter of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Jim Mone)

Dallas Cowboys wide receiver Dez Bryant is tackled by Minnesota Vikings cornerback Cedric Griffin after making a reception during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Charlie Neibergall)

Dallas Cowboys quarterback Tony Romo throws a pass as he is pressured by Minnesota Vikings defensive end Jared Allen (69) during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Minnesota Vikings quarterback Donovan McNabb throws a pass during the first half of an NFL preseason football game against the Dallas Cowboys, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Dallas Cowboys running back Felix Jones celebrates with teammate Kyle Kosier (63) after scoring a touchdown during the first half of an NFL preseason football game against the Minnesota Vikings, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Minnesota Vikings running back Adrian Peterson, top, looks run past Dallas Cowboys cornerback Orlando Scandrick during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Dallas Cowboys cornerback Alan Ball returns a blocked field goal for a touchdown during the first half of an NFL preseason football game against the Minnesota Vikings, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Jim Mone)

Minnesota Vikings wide receiver Emmanuel Arceneaux catches a pass over Dallas Cowboys cornerback Josh Thomas, left, during the second half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Dallas Cowboys quarterback Tony Romo is sacked by Minnesota Vikings defensive tackle Christian Ballard, left, and defensive end Brian Robison (96) during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Dallas Cowboys running back Felix Jones looks to break a tackle by Minnesota Vikings defensive end Brian Robison during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Jim Mone)

Minnesota Vikings running back Adrian Peterson (28) runs from Dallas Cowboys defensive tackle Jay Ratliff during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Jim Mone)

Dallas Cowboys wide receiver Dez Bryant looks to break a tackle by Minnesota Vikings cornerback Cedric Griffin (23) during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Jim Mone)

Dallas Cowboys head coach Jason Garrett looks on during the second half of an NFL preseason football game against the Minnesota Vikings, Saturday, Aug. 27, 2011, in Minneapolis. Dallas won 23-17. (AP Photo/Jim Mone)

Minnesota Vikings running back Lorenzo Booker (27) is tackled by Dallas Cowboys linebacker Bradie James (56), cornerbacks Orlando Scandrick (32) and Bryan McCann, left, during the first half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Dallas Cowboys running back Tashard Choice is tackled by Minnesota Vikings linebacker E.J. Henderson, right, and linebacker Larry Dean, rear, during the second half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. (AP Photo/Andy King)

Minnesota Vikings quarterback Christian Ponder throws a pass during the second half of an NFL preseason football game against the Dallas Cowboys, Saturday, Aug. 27, 2011, in Minneapolis. Dallas won 23-17. (AP Photo/Andy King)

The Minnesota Vikings host the Dallas Cowboys in an NFL preseason football game Saturday, Aug. 27, 2011, in Minneapolis. Dallas won 23-17. The Vikings were playing their first home game since the roof collapsed in a snowstorm last December. (AP Photo/Andy King)

Minnesota Vikings tight end Allen Reisner (89) is tackled by Dallas Cowboys safety Danny McCray (40) and linebacker Kenwin Cummings (54) during the second half of an NFL preseason football game, Saturday, Aug. 27, 2011, in Minneapolis. Dallas won 23-17. (AP Photo/Andy King)

Dallas Cowboys quarterback Tony Romo (9) runs off the field after an NFL preseason football game against the Minnesota Vikings, Saturday, Aug. 27, 2011, in Minneapolis. Dallas won 23-17. (AP Photo/Jim Mone)