Manchester United defender Lisandro Martinez during the 1-1 draw against Rayo Vallecano in the pre-season friendly match at Old Trafford, Sunday July 31, 2022.

Watch: Carragher brutally dissects Man Utd’s Lisandro Martinez issue

Former Liverpool defender Jamie Carragher is convinced that Lisandro Martínez can’t play in a back four at Manchester United due to his height.

Martinez spent three years working under current United manager Erk ten Hag at Ajax and won their Player of the Year award in 2021-22.

Ten Hag wanted to bring the Argentina international to Old Trafford and United agreed to pay an initial £48.3million to secure his signature. But he stands at just 5ft 9in, making him the smallest senior centre-back in the Premier League.

Martinez made his United debut in the 2-1 defeat to Brighton and was fortunate not to concede a penalty for a foul on Danny Welbeck.

The 24-year-old was then substituted at half-time against Brentford after United conceded four first-half goals at the Gtech Community Stadium.

“We knew we’d more likely either win it or the second ball around it,” Brentford manager Thomas Frank told Sky Sports when asked whether his side deliberately targeted Martinez.

“Of course we looked at what Brighton did well against them, and Brighton are also like us in the way they want to play. Normally Brighton always build from the goalkeeper, but they went long every single time so of course we looked at that.

“We knew we had that weapon so that’s why we did it.”

United’s 4-0 defeat to Brentford was unsurprisingly one of the biggest talking points on Monday Night Football.

Carragher decided to focus on Martinez, and he believes that United will continue to struggle if they keep playing him at centre-back.

“We should never judge managers [or] players too early but I’m convinced this can’t work, because of the size of him in a back four,” Carragher said.

“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.”

He added: “Brighton are one of the best passing teams you’ll see in the Premier League. So against Manchester United, they actually went 20 per cent long with their passes, the second-highest they’ve done since August 2021, the start of last season.

“Last season’s average was 12 per cent, so they doubled what they were doing because of the size of the Manchester United centre-back. Brentford’s manager, Thomas Frank, mentioned what Brighton did after the game. They went from 16 per cent to 21 per cent, again another jump.

“And the reason why they’re gonna have a huge problem with [Martinez] at centre-back is every single team that play Manchester United, maybe bar Manchester City and Liverpool, who might feel, ‘we don’t need to change for Man United’ – should target that. And if they don’t, they’re crackers.

“They really should do that and I think [United] have got a huge problem. And Ten Hag has got his fingerprints a little bit over this team, and the two or three things I think he’s influenced are not working.”

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