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 took a closer look 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. The union has hired neurologists to examine the policy and determine whether any changes are needed to prevent players from playing with an undiagnosed concussion.