Police said Saturday that 23-year-old Michael Adams told officers that three men confronted him shortly after 3 a.m. Saturday on the city's South Side district.
He said he didn't have his keys with him and "the situation escalated," and one man pointed the gun at his face while the other stabbed him twice before all three fled.
Adams was reported in stable condition at UPMC Mercy after surgery for stab wounds to the abdomen and left forearm.
Adams was drafted in the second round last year and named the team's outstanding rookie, starting six of the 10 games in which he played.
He tweeted that he "had an angel" looking out for him.