The 30-goal striker needed an operation after rupturing the ligaments in his knee during the first leg of the play-off semi-final against Brighton and will be out for up to nine months.
He will be hoping to return as a Premier League player after Palace beat their rivals 2-0 in the second leg to set up a winner-takes-all clash with Watford at Wembley next Monday.
Holloway said: "It's an occupational hazard but it's a terrible scenario for him after his best season ever.
"He just went to turn and before you know it he's badly damaged his knee.
"But he will get fit again, he's ready to work hard and he's a very special fella. He doesn't get too high and he doesn't get too low.
"He has totally convinced me that he is going to be fine and in the meantime it gives someone else a chance."
- Sports & Recreation