Dirk Nowitzki said he had an MRI on his left knee Thursday. He said the knee hasn’t given him any difficulties, but given that he had to have arthroscopic surgery on his right knee in October, he wants to make sure the left one is sound. Nowitzki said he won’t know the results of that MRI until Friday. Also on Friday, he plans to have examinations, and probably X-rays, of his feet and ankles. He said he experienced bone spur problems in the last couple of weeks of the season, something he had not experienced in several seasons. “It’s not good news, I guess, that they’re flaring up,” he said. “We’re going to have our doc check that tomorrow, probably get some X-rays and see if my feet got worse.”