MINNEAPOLIS — The Vikings have called teams to see what they would be willing to offer in exchange for backup quarterback Tarvaris Jackson, according to a league source.

The Vikings have four quarterbacks on their roster, which must be trimmed to 53 players by Saturday. Coach Brad Childress said recently the team possibly could keep four quarterbacks, but it seems more likely that it will trade or release one.
Jackson has been the subject of trade rumors since Brett Favre arrived. However, it remains unclear which direction the Vikings will go if they are unable to trade Jackson.
Jackson, who started 20 games in his first three seasons with the team, admitted he feels a sense of uncertainty about his situation, but he said he is focused on preparing for Friday’s preseason finale against the Dallas Cowboys.
“You never know with this business, period,” he said. “I just take it as it is. Whatever happens, happens. I can’t control it. I just try and get better, that’s it. I can’t worry about (whether he gets traded or released). I’m not worried about it because I can’t control it. Whatever is going to happen is going to happen whether I worry or not.”
Childress said Favre will not play Friday (teams typically rest their starters for the final preseason game) so that means Jackson, Sage Rosenfels and John David Booty will split playing time.
“I feel certain that I can play well in this league,” Rosenfels said. “When this team needs me, I can play at a very high level, and I think I’ve played pretty well this preseason. I think I’ve played well since we left Mankato and at the end of Mankato. I think I’m playing high quality football. My goal is to continue to play at a high pace.”