Eric Cantona has compared watching Manchester United play to "making love as an old man".
United are eighth in the league, seven points off a top-four place after losing at bottom-of-the-league Watford last weekend following a draw at home to Everton.
"Manchester United occupies a special place in my heart," the former United striker, who won four Premier League titles during his time at the club, told Otro in a festive message.
"But watching United play now, it's a bit like making love as an old man. You try as hard as you can, but at the end of the day, everyone is a bit disappointed."
Cantona added: "When I say things, sorry, about making love as an old man, I'm not speaking about me. It was just a metaphor."
Ole: We need to follow Liverpool example
United have the fewest points (25) they have ever had at Christmas in the Premier League era, as their hopes of a top-four finish continue to dwindle.
Boss Ole Gunnar Solskjaer admits his team are not where he wants them to be, but it is confident they will make progress in a similar way bitter rivals Liverpool have in recent years.
He said: "We want to be a team that can go and dominate teams and break teams down. It's taken Liverpool a few years to get to that stage and we need to just keep on building because that's what we want to get to.
"Yes, we're good at counter-attacking. Yes, we've got pace and fast players. We should always keep that because it's in our tradition.
"We create loads of chances, but every time we lose it there's a counter-attack. We need to lock it down more, better at stopping the counter-attack.
"That's where this team is going to learn and grow and I'm sure we'll see an improvement over this season and the next year."
Pogba 'the best all-round midfielder in the world'
Paul Pogba could make his first start since September when United host Newcastle on Boxing Day after the midfielder came off the bench to make a return to action in the 2-0 defeat at Watford.
Solskjaer is delighted to have Pogba fit and available, describing the France international as "the best all-round midfielder in the world".
"He can play anywhere, he can play the whole midfield, he is a box-to-box midfielder," Solskjaer said. "He can drop deep, get it and play them long passes. He can get higher up and combine like he did on Sunday.
"It depends on the game. That's the beauty of having Paul because he is the best all-round midfielder in the world, he can do all the roles. It's great to have him back"