Taj Gibson celebrated the birthdays of Jerry Reinsdorf and Joakim Noah on Monday by having an MRI performed on his sprained left knee. Well, not really, but the confluence of such events seemed fitting for a star-crossed Bulls team these days. For every celebratory moment — a blowout win in Charlotte, Noah turning 28 — a somber one follows in the form of a convincing loss to an elite team or another injury. At least Gibson's MRI didn't reveal a torn ACL, although it did confirm a sprained MCL that could sideline the defensive-minded forward up to two weeks. Fortunate, too, is the fact the Cavaliers come to town Tuesday, a team the Bulls have solved 11 straight times by an average of 17.8 points. Then again, with previous losses to such downtrodden teams as the aforementioned Bobcats, Suns and Hornets, the Bulls have proved consistently how small their margin of error remains. Schedule an elite opponent and that margin drops basically to zero. Coach Tom Thibodeau has mastered the phrase "we have more than enough to win," an admirably tough-minded approach to eliminating excuses. Impressive, too, was Noah glumly sitting in his locker stall in Oklahoma City late Sunday, on the eve of his birthday, pointing the finger inward. "It starts with myself," Noah said. "I have got to play better."