A 25-year-old man has been arrested on suspicion of assaulting a police officer at the Old Trafford protests earlier this month.
Manchester United fans rallied against their owners, the Glazer family, ahead of their match with Liverpool on 2 May.
While most of the demonstration was peaceful, there were scenes of violence as the contest had to be postponed, with the rescheduled clash taking place on Thursday night.
One police officer was left with serious facial injuries after having an object thrown at him.
And Greater Manchester Police confirmed an arrest has been made in connection to that assault.
A statement read: “Today officers executed a warrant at an address in the Prenton area of the Wirral.
“A 25-year-old man was arrested on suspicion of section 18 wounding, violent disorder and burglary. He remains in custody for questioning.
“The arrest was in relation to a breach of the Manchester United grounds and an officer who was left with a broken eye socket, broken nose and a slash to the face after an object was thrown at his face.
“He continues to receive medical treatment for his injuries.”
Security measures have been ramped up ahead of Manchester United’s home clash with Leicester on Tuesday night.
Red Devils manager Ole Gunnar Solskjaer has pleaded for there to be no violence if supporters choose to protest again.
He said: “Security measures are being looked at, of course, and I hope that we can keep the protests – if there are protests – down to loud voices, nothing violent.
“We want to listen. The players want to play the game. We play Liverpool. Of course we want to beat Liverpool, we want to beat Leicester.
“So, we’re going to do everything we can for our fans to celebrate what we’re doing on the pitch.”