Martinez doubled down on his criticism of United’s hierarchy but did not apologise following the club’s 2-0 defeat to Atlético Madrid earlier this week.
The defender ripped into technical director Jason Wilcox, the lack of investment in the United side, suggested manager Michael Carrick has not been backed enough, whilst constant managerial changes have hurt the side.
Are Man Utd a circus?
Wayne Rooney, Jamie Carragher and Ashley Young are just a few names that have criticised Martinez’s original comments and now Keane, speaking on The Overlap, compared United to a circus in the latest attack on the club.
"There will be some fans saying it's great and some saying you're letting the team down, especially from a player who hasn't been at his best, when the team is struggling," he said.
"I think as a reflection of the club, it's obviously chaos there, like a bit of a circus.
"When you're going through a difficult spell like United are, the issue I have with certain players saying things is you always have to start with the man in the mirror before you start coming out with all these comments.
"I don't think it will be a big falling-out - because I think we have question marks over this dressing room anyway," Keane said.
"I don't think there's enough characters - enough men in there - but I don't see him as a senior player at Manchester United. I see him as a centre-half who's making lots of mistakes."
Many teammates reportedly agree with Martinez’s underlying criticism of recruitment and a lack of squad depth, with some even confronting him on the plane.
Martinez, 28 years old, is out of contract at the end of the season, though United have the option to extend his deal by another year.
Without an apology Martinez is unlikely to stay as the drama continues and reports are already suggesting that he may make the switch to European rivals Atletico Madrid in January.