Who's the quarterback?

Unless his name is Manning, he's likely part of a battle to see who will start - not really, it only seems that way, doesn't it?

While the Broncos, Raiders and Rams top the list of teams using training camp to pick a starter, many teams have issues at other positions.

With so many top players changing teams, it's easy to see why coaches are set to make tough decisions on starters when the regular season opens Thursday, Sept. 9 with the Minnesota Vikings (with or without Brett Favre) at the Super Bowl champion New Orleans Saints.

Here's a six-pack of some of the better duels for starting roles.

-Raiders: QBs Jason Campbell vs. Bruce Gradowski: Campbell, acquired from the Redskins after JaMarcus Russell was cut, opened camp as starter. Gradowski missed three months with torn pectoral muscle and has to play catch-up.

-Broncos: QBs Brady Quinn vs. Kyle Orton: Orton (3,800 yards in '09) opens camp as starter, but has to prove he's better than Quinn ... And Tim Tebow looms.

-Redskins: RBs Clinton Portis vs. Larry Johnson: This could be interesting: Two players used to starting, known for speaking their minds and fighting the perception their careers are in decline.

-Rams: QBs Sam Bradford vs. A.J. Feeley: Marc Bulger is gone, so free-agent signee Feeley is the man for now. No. 1 overall pick Bradford will eventually show up at camp, and the competition will begin.

-Cowboys: WRs Roy Williams vs. Dez Bryant: OK, the pads are off in this one. Rookie Bryant refused to carry Williams' pads during a workout; the competition or playing time should be fun to watch.

-Bengals: WRs Chad Ochocinco vs. Terrell Owens: Not a battle for playing time between longtime friends, but for face time. Big question is who will face more double teams if Owens shows he can hang on to the football?