LaMarcus Aldridge will rest in back-to-back games against Utah and Denver
He has a sore right knee

As reported by ESPN:
"LaMarcus Aldridge will be held out of this back-to-back at Utah and Denver headed into the All-Star break to receive treatment on his sore right knee. There isn't an injury or anything, just pre-planned maintenance. He's gone back to San Antonio to receive treatment, but will definitely be participating in the All-Star game."