Benteke has struck 22 goals this season, including Monday's superb hat-trick against Sunderland.
"Christian is a natural monster," said Delph. "He doesn't do any upper body work whatsoever. He works on his core strength and his legs but that is it.
"When he first came I asked him whether he ate raw meat. John Carew was very similar but Christian is 22.
"Some defenders try to rough him up but everyone who has tried it has failed."