Associated Press Dirk Nowitzki went through a full practice with the Dallas Mavericks on Friday after having his swollen right knee drained for the second time in a month. Nowitzki says he doesn’t know why the swelling keeps coming back and that arthroscopic surgery remains an option if it keeps happening. Nowitzki says he will not play on a swollen knee all season. It is the same knee and same issue Nowitzki dealt with early last season. The Mavericks will scrimmage as part of a fan day Saturday. Nowitzki, who is going into his 15th NBA season, plans to see how his knee responds over the weekend and is hopeful that it will be all right. The perennial All-Star forward didn’t play in the Mavericks’ loss Tuesday at FC Barcelona Regal in Spain.