Mar. 13—If Oklahoma wanted to ensure it would be an easy pick for the NCAA Tournament, ESPN’s Joe Lunardi predicted it would need to pick up one win at the Big 12 tournament. After falling to TCU 77-70 on Wednesday in a game that they trailed for all but 19 seconds, the Sooners can no longer be certain of their postseason plans. They were already in for a tough test with Javian McCollum, Rivaldo…