After the Red Devils edged past FC Rostov 1-0 (2-1 on aggregate) at Old Trafford in the UEFA Europa League on Thursday, Mourinho said his team will "probably lose" to Middlesbrough on Sunday in the Premier League, having played three games in a week.
He's manager of Manchester United, one of the biggest clubs on the planet, the squad he's got, the players and he keeps moaning about fixtures and fatigue.
We were just looking at some of the cup draws they've had. They've had an easy way in the cups, some good draws, a lot of home draws, and the guy is talking absolute nonsense.
I've never heard so much rubbish in my life. Maybe the club is too big for him, he can't deal with all these demands at the match. What matches? Man United reserves could've won that game.
The United legend also suggested that Mourinho passing a banana on to the pitch for defender Marcos Rojo was just for show. "I think that was all staged, without a shadow of a doubt," he said on ITV (h/t the Irish Independent).
Keane, a seven-time Premier League champion with the Red Devils, is known for his forthright opinions on football, and his views will strike a chord with some supporters. Bleacher Report's Rob Blanchette is unsure whether the Irishman has a case, though:
United made hard work of the second leg against Rostov. After failing to take their chances in the first period, Juan Mata struck in the 70th minute to settle any nerves at Old Trafford, although Sergio Romero was on hand to make two excellent saves late on to prevent the tie from going to extra time.
It meant what should have been a comfortable evening for United became a draining one, mentally and physically. Indeed, they lost record signing Paul Pogba to injury during the game.
Mourinho spoke of how difficult it will be for his players to be at their best when they visit the Riverside Stadium on Sunday for a midday kick-off.
"The reality is we have lots of things going against us, and we have to fight," he said, per Jake Polden of the Daily Mirror. "So the boys are amazing boys, and probably we will lose the game on Sunday, but we will try our best."
While Keane may have slaughtered Mourinho for his suggestions, AFP's Tom Williams believes the coach is using one of his distraction techniques:
United do have one of the biggest squads in European football and should be able to cope with the demands of competing on multiple fronts. Even so, playing three games in seven days is a huge test of any team, and with that in mind, Mourinho is clearly trying to take some pressure off his tired troops.
That's not out of the Keane book of leadership. During United's dominant years in the Premier League, the midfielder was never a man to show weakness, and it's easy to see why such comments would irk him.