File-This May 27, 2015, file photo shows Golden State Warriors guard Klay Thompson on the court after being injured during the second half of Game 5 of the NBA basketball Western Conference finals against the Houston Rockets in Oakland, Calif. When NBA union chief Michele Roberts watched Stephen Curry return to a game after his head slammed against the floor and he walked woozily to the locker room, she immediately boned up on the league's concussion protocols. Two nights later, when Curry's Golden State teammate Klay Thompson was cleared to return after being kneed in the head only to later be diagnosed with a concussion, her reaction was much stronger. "It mortified me," she said. (AP Photo/Tony Avelar, File)