If he's healthy, you have to start Kolb. Not because he gives you the best chance to win (winning is a secondary concern right now, since the coaching staff isn't on a directly hot seat), but because you must find out if he has any future with the team.
If there's going to be a legitimate quarterback competition come 2012 training camp, then Kolb has to start building credibility with his teammates. Dude has Fitz in his corner and the head coach, but that can only last so long.
Kolb probably deserves a chance to make the case that the Cards shouldn't invest a 1st round choice in a quarterback in the 2012 NFL draft.
But Kolb isn't healthy, so he'll get another week off and have a chance to make his case over 4 home games and 1 road game, where it might be much easier for him to succeed.