The 24-year-old faces missing the Hammers' next two matches - against Arsenal in the EFL Cup and Newcastle United in the Premier League - after being charged for an alleged dive at the bet365 Stadium.
United have until 6pm on Tuesday to put together a case against the possible suspension, which would make the Argentine ace just the second Premier League player to be punished for diving with retrospective action.
"I'm going to think about it. I'm a bit surprised," he told reporters. "The referee was 10 yards from the ball, nothing was blocking his vision, the defender made a challenge for the ball and didn't get it. So, I think they're going against the referee.
"The Goals on Sunday panel all said it was a definite penalty. We're going to think about whether we appeal or not. I think it's strange that three people on Sunday thought it was a penalty and three people today think it probably wasn't.
"He had a brilliant performance on Saturday, he made two assists, so I only said to him after the game about how well he played. Let me be clear. I'm the first one who wants to get rid of diving. That's why I'm surprised by this one because nobody can be sure."