Chelsea manager Carlo Ancelotti will review Michael Essien's tackle on Clint Dempsey before deciding whether to appeal against the Ghanaian's red card.
Essien saw straight red for a two-footed challenge on Dempsey after he had scored the only goal in Wednesday's 1-0 win over west London rivals Fulham.
"He tried to do a tackle, and he won it," said Ancelotti. "I'm not sure it was a sending off.
"We have to wait. I want to watch the replay before doing anything."
Essien was making his return to the Chelsea side after two games out with a toe injury, one of which was last Sunday's 2-0 defeat at Liverpool.
It appeared as though all was going to plan, with his 30th-minute header setting the Blues on course to a deserved victory that takes them four points clear of Manchester United at the top of the Premier League.
However, the midfielder went from hero to villain in the fifth and final minute of injury time when he leapt two-footed into a tackle with Dempsey that saw him win the ball, but was deemed dangerous enough to warrant instant dismissal by referee Martin Atkinson.
"I don't like to judge the decision," continued Ancelotti. "But I can say that maybe it was not a red card because Essien made a strong tackle, but on the ball.
"There was not a risk on the opponent. I think he went for the ball, the last ball of the game, an important ball."
Despite the sour end to the game, Ancelotti declared himself pleased with his side's display that earned them important points as Manchester United were drawing 0-0 with local rivals Manchester City.