The Spurs are currently 4-5, and might be looking at 4-6 (down to the Jazz atm).
Granted, they've had some key injuries (to Parker, Ginobili, and Duncan, once again). However, the fact that they're below .500 regardless of these injuries ought to be pretty troubling to fans of a team that was supposedly looking at 2nd best or best in the West before the start of the season.
So...should Spurs fans be worried? Are the Spurs really a contender? Yeah, maybe part of it is that Popovich doesn't care about the regular season, and certainly a part of it is the injuries, but surely their ability to contend will in part center on their playoff seed and their health as a team.