Fellaini conceded an 87th-minute free-kick at Old Trafford when he grabbed Guendouzi's hair and was penalised by referee Andre Marriner.
Marriner decided against showing Fellaini a yellow card for the foul, despite his attempt to gain an advantage possibly constituting unsporting behaviour.
However, Fellaini will face no further action from the Football Association as the incident was spotted by referee Marriner.
Fellaini received a retrospective three-match ban in May 2016 for elbowing Robert Huth after the former Leicester City defender had pulled his hair.
On that occasion, the scuffle between Fellaini and Huth was not spotted by referee Michael Oliver. Huth also received a retrospective three-match ban.
Louis van Gaal, then manager of Manchester United, complained at the time that Huth's pull should have been spotted by the team of officials.
"It's not in the books that someone has to grab by the hair and then pull it behind - only in sex masochism," he said.
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