Belgium international Fellaini grabbed his opponent by his hair as he attempted to accelerate away from him in the second half of the 2-2 draw at Old Trafford.
The incident happened right under the nose of referee Andre Marriner although a free-kick was the only punishment dished out, with Fellaini escaping without a caution.
Speaking to RMC Sport about Fellaini's bizarre decision to pull him back by the hair, Guendouzi jokingly said: "I think there is a bit of jealousy there. Maybe he can’t accept the fact that he chose to go back to short hair!"
With the referee having dealt with the incident at the time Fellaini will likely escape any retrospective punishment.
The same couldn't be said for former Leicester City defender Robert Huth, however, with the German involved in a similar hair-pulling incident, ironically with Fellaini, during a Premier League game in 2016.
He was handed a retrospective three-match ban in the aftermath of that particular incident and he couldn't help but offer his view after seeing Fellaini pull Guendouzi's hair on Wednesday night.
He tweeted: "Looks like I taught him well... #playon."
Guendouzi has made 12 league appearances for the Gunners since his move from Lorient in the summer and he insists he was pleased with his performance at Old Trafford on Wednesday night, despite a difficult start.
"I try to give my best each game," he added. "I didn't start this game very well. I needed 20-30 minutes to get used to the intensity but after that it was great. I'm happy about what I did [in the game].
"It's true that we had many situations to score. We could have killed the game off later I think. United were efficient. They scored two goals that we could have avoided. We made some mistakes but we did a great game."
The Gunners had twice taken the lead in the match only for goals from Anthony Martial and Jesse Lingard to peg back Unai Emery's men.