
Tarvaris Jackson and Sage Rosenfels also will be a focus of attention, as they are expected to split time in the second half. Jackson and Rosenfels have gone from competing for the starting job to vying for the No. 2 spot behind Favre -- or perhaps a spot on another NFL roster. Unless the Vikings go with the unusual step of keeping four quarterbacks, either Jackson, Rosenfels or John David Booty is going to be the odd man out. Favre is scheduled to play the entire first half tonight; Jackson is expected to play the third quarter and Rosenfels the fourth.The Vikings almost certainly would consider taking a late-round draft pick in exchange for Jackson. Rosenfels signed a three-year, $9 million deal upon his arrival with the Vikings last February, making him the most logical guy to stick behind Favre. Rosenfels' contract is very reasonable for a backup quarterback, and keeping Rosenfels on the roster means the Vikings would have a set backup plan for next season if Favre did not return for a 20th season.