Vokoun had been hospitalized since Saturday when he had a procedure performed to dissolve a blood clot in his pelvis.
There is no timetable for him to return to the team.
Vokoun went 13-4-0 with a 2.45 goals-against average in 20 regular season games for the Penguins last season, and went 6-5 with a 2.01 GAA in 11 Stanley Cup Playoff games. He replaced Marc-Andre Fleury as starter for Game 5 of the team's first-round series against the New York Islanders, and backstopped the Penguins to the Eastern Conference Final.
I don't have a crystal ball. Predicting is a real complicated thing. If we stay healthy, have enough depth and get the good goaltending we think we're going to have, you can go all the way. But a lot of things have to happen. There's going to be a lot of teams that think the same thing. Everyone made deals. We're all are optimistic about where we'll end up.
— Rangers general manager Glen Sather after being asked if he's constructed a team that can win the Stanley Cup before their 4-1 win against the Predators on Monday