Liverpool legend Jamie Carragher issued an apology over his doubts regarding Manchester United ace Lisandro Martinez.

Carragher was vocally critical of United signing Martinez to play at centre back, given his lack of height.

Despite early struggles, the Argentine went on to have an outstanding season for the Red Devils before an injury cut short his campaign.

"The other problem he (United boss Ten Hag) has got is the signing of Lisandro Martinez," Carragher began on Monday Night Football early in the season.

"Now, we should never judge managers or players too early, but I'm convinced this can't work because the size of him playing in a back four. Maybe he could go left-back, maybe he could play in a back three, but in a back four, he cannot play there in the Premier League."

This week, he stated: “That was not about Lisandro Martinez, but any central defender in the Premier League who is under six foot tall. But he has not.

“Any player is going to have weaknesses, whether its physically or technically and the best players hide their weaknesses. Everyone has them.

“I was not the tallest player and I was always worried that I was going to get 'found out' or sort of bullied in the air. At times you lose big challenges and goals, while he is three or four inches smaller than me."

Carragher added: “We have spoken about the significance of Casemiro being absent from United's team but the same is true of Martinez. Not just defensively, but also his ability on the ball and playing out from the back.

“He is a warrior and a leader. He and Casemiro are the two new signings who have transformed Man United. So apologies to Lisandro Martinez and Man United fans, you can stop tweeting me now about it!"