Berba signed for the Cottagers on transfer deadline day from Manchester United.
Gray told talkSPORT: "He [Berbatov] would have been a perfect fit for Liverpool.
"He could have played up front with Luis Suarez.
"There's absolutely no way Sir Alex Ferguson would have sold him to Liverpool in the first place, but he is the type of player that could have gone into that Liverpool side and stitched everything up.
"It would have allowed Suarez to play in his best position, just off the front, as a creator and part-time scorer rather than as a full-time goal scorer, as he's playing at the moment."