The Seagulls face off with Erik ten Hag's Reds at Wembley in a 16:30 BST kick-off, with both sides vying for a spot in the final, which will be played in June.
It was thought that De Zerbi would be without Steele, Veltman and Ferguson for this clash. Steele was absent with a 'slight injury' against Chelsea last week and both Veltman (hamstring) and Ferguson (ankle) had to be replaced in the game at Stamford Bridge.
The Italian had previously indicated that the trio would be ruled out of the semi-final, but he now appears to have changed his tune.