Manchester United manager Ole Gunnar Solskjaer spoke to a group of fans who took their protests against the Glazers to the training ground on Thursday.
The Old Trafford giants have been under the American family's ownership since they completed their controversial takeover of the club in 2005.
Their reputation managed to sink to a new low in recent days after attempting to launch the European Super League, with United co-chairman Joel Glazer named vice-chairman of the breakaway competition.
But the proposed league swiftly and spectacularly unravelled. United announced executive vice-chairman Ed Woodward would leave by the end of the year and Glazer admitted "we got it wrong" in an open letter to fans.
But anger remains strong and a group of around 20 fans protested against the owners at the club's Carrington training base on Thursday.
United said in a statement: "At approximately 9am this morning a group gained access to the club training ground.
"The manager and others spoke to them. Buildings were secure and the group has now left the site."
The Red Issue Twitter account showed an image of fans on a training pitch with a banner reading 'Glazers Out' and another saying '51% MUFC 20' in reference to the model of ownership used widely in Germany.
In another image, protesters are shown holding a banner reading 'we decide when you play' outside the entrance to the main training ground building.
It is the latest example of fans of the so-called "Dirty Dozen" clubs protesting at the decision. Supporters from the likes of Chelsea, Tottenham, Liverpool and Real Madrid have all made their feelings clear in recent days.
Glazer has not attended a United game in over two years and his apology speech marked his first communication with supporters in almost 16 years.
First team pitch: pic.twitter.com/lbVGzk9rhl
— Red Issue (@RedIssue) April 22, 2021
The letter read: "You made very clear your opposition to the European Super League, and we have listened. We got it wrong, and we want to show that we can put things right.
"Although the wounds are raw and I understand that it will take time for the scars to heal, I am personally committed to rebuilding trust with our fans and learning from the message you delivered with such conviction.
"We continue to believe that European football needs to become more sustainable throughout the pyramid for the long-term. However, we fully accept that the Super League was not the right way to go about it.
"In seeking to create a more stable foundation for the game, we failed to show enough respect for its deep-rooted traditions – promotion, relegation, the pyramid – and for that we are sorry.
"This is the world's greatest football club and we apologise unreservedly for the unrest caused during these past few days."
Solskjaer is due to speak publicly on the Super League for the first time at his next press conference on Friday.
