PORTLAND, Ore. — Spurs star Victor Wembanyama is officially available for Game 4 against the Trail Blazers in Portland on Sunday afternoon after clearing the NBA's concussion protocol . The 7-foot-4 MVP candidate was a true game-time decision after falling onto his chin less than a week ago and missing Game 3. When Spurs coach Mitch Johnson addressed the media an hour and a half before tipoff, he said that Wembanyama was "still working through the process" and they'd have an official update an hour before the game. When the time came, San Antonio said Wembanyama would be available. Wembanyama set a Spurs record with 35 points in his playoff debut in Game 1, then became the first unanimous Defensive Player of the Year in league history, then fell on his face in the second quarter of Game 2. Clearly dazed, he went to the locker room and was diagnosed with a concussion.…