Tevez's high boot caught the thigh of the United defender in a 50-50 tackle, and Ferguson believes the challenge was severe enough to warrant a dismissal.
"Tevez should have been sent off really," said Ferguson. "Have you seen the tackle? He went over the top of the ball. He didn't even get booked."
Ferguson's views have emerged ahead of the return leg at Old Trafford on Wednesday, when emotions are expected to be running high amid the fallout from Tevez's clash with United stalwart Gary Neville.
In celebrating his first goal against United last week, Tevez made a "shut it" gesture in response to pre-match comments from Neville that the Argentina star was not worth the money it would have cost United to keep him at Old Trafford last summer.
Neville responded with a one-fingered gesture, which prompted further reaction from Tevez, who followed up by winning the game with a second-half header and then aimed fierce criticism at the Red Devils skipper.
In a wide-ranging attack, Tevez labelled Neville "a moron" and "a boot-licker".