Romelu Lukaku should be slapped with a three-match ban by the FA for kicking out at Brighton defender Gaetan Bong, according to Graham Poll.
The flashpoint occurred during the 1-0 win at Old Trafford as the Manchester United striker was caught on camera lashing out at the Seagulls full-back.
Lukaku escaped punishment from referee Neil Swarbrick, who let play continue ahead of the crucial winner.
However, United are sweating over potential retrospective action, which could see him miss the games against Watford, Arsenal and Manchester City if hit with a ban.
Former Premier League ref Poll told the Daily Mail: "Lukaku was impeded as the corner came in but his reaction was extreme, kicking out first with his right foot and then making full contact with his left foot somewhere quite painful.
"It was a violent act which would have resulted in a red card had referee Neil Swarbrick seen it. The Brighton full back did remarkably well to not react, nor complain to the officials.
"United manager Jose Mourinho will be understandably irritated if Lukaku is banned retrospectively after [Shane] Duffy escaped, but he should take comfort in the three points because the only goal of the game — Ashley Young’s deflected effort — came just after the whistle should have blown for Lukaku’s assault."
Meanwhile, Mourinho has praised Lukaku’s work ethic and slammed United players who can’t match it.
Despite the forward's barren run, Mourinho refused to criticise the £75million striker and said he wished more of his players would put as much effort in.
Asked about the workload on Lukaku, Mourinho said: “In the last minute he was fighting and running back like he was in the first minute.
“The way Romelu wins the corner for the goal, the way he ends the game making tackles in the left-back position, that’s the mentality I want.
“Unfortunately, not every player is the same. Some are capable of going to the limit of their efforts but others, even with a lot of talent, are not able to.”