Bears all passed their conditioning tests Wednesday in 100-degree heat and high humidity ahead of Thursday's first day of practice at Bourbonnais as they embarked on a season that could be win-or-else for coach Lovie Smith, and possibly for many of the 17 starters whose contracts expire over the next two seasons.  
Brian Urlacher, who had nursed a knee sprained in the regular-season finale, and tackle Gabe Carimi, who had two surgeries to the same knee last season. It's possible coach Lovie Smith will give Urlacher and some of the veterans days off to rest at times during camp as he has done in the past, but those would be unrelated to recovery from any old injuries.  

Johnny Knox, who went on the preseason version of the physically unable to perform list. The back surgery he underwent late last season kept him from getting into the kind of shape he'd need in order to start practices. He is in Bourbonnais, but doing rehab work rather than practicing with the team. The realistic goal is to get him ready for 2013, but because he hasn't yet been placed officially on PUP for the regular season there remains at least a little hope he might get into the kind of shape he'd need to be in to return to the team in October.

Follow Bears reporter Gene Chamberlain on Twitter@CBSSportsNFLCHI.