Chelsea manager Jose Mourinho has been asked by the Football Association to explain his post-match comments after his side's 1-0 win over Wigan.
The FA wants Mourinho to explain his claim that Wigan midfielder Lee McCulloch was "cheating".
It is also looking into comments made by Manchester United boss Sir Alex Ferguson after the draw with Everton.
"We maybe could have had a penalty but there's no way Rob Styles was ever going to give us a penalty," he said.
English football's governing body is believed to be considering whether under-pressure Ferguson placed a question mark over the integrity of Styles.
The referee failed to give a spot-kick for a challenge by central defender David Weir on striker Louis Saha and Ferguson's response is likely to form the basis of whether any action is taken against him
But it is Mourinho's comments that are potentially the more serious.
Mourinho told defender William Gallas not to give possession back to Wigan during the game after David Connolly had played the ball out, with team-mate McCulloch laying on the ground clutching his ankle.
"We know what fair play is and when a player is injured, we give the ball back," said Mourinho after the game.
"When a player is cheating, we are not stupid.
"Because the player was cheating and seconds later stood up and was running again, I told William Gallas not to give them the ball back.
"It is my responsibility and I will do it again. Fair play is not to cheat. It is one thing to be injured and another to pretend to be injured."
Mourinho was fined £5,000 last season when he alleged Manchester United players were guilty of "fault and fault and cheat and cheat" during a Carling Cup semi-final clash.