Manchester United have been warned against signing Borussia Dortmund captain Mats Hummels during the summer transfer window.

The Germany World Cup winner has been constantly linked with a move away from Dortmund, who are bottom of the Bundesliga after just four wins in their 18 league matches, with latest reports claiming United could pay £37m to secure his services this summer.

Hummels has constantly flirted with the idea of leaving for pastures new but former United and Bayern Munich midfielder Owen Hargreaves says manager Louis van Gaal should refrain from making the player his marque addition during the summer.

"No. He is a super ball-playing centre-back but I don't think he can defend, he is too slow," Hargreaves told BT Sport. "I think he is Franz Beckenbauer, the new version. Super passes but if I am Man United I want Vidic, I want Kompany.

"He's a nice football player, easy on the eye, but I just feel Man United need a physical presence. He's the captain of Borussia Dortmund, they're last in the Bundesliga. Is that the measuring stick for a club like Manchester United? I am not so sure."

The 26-year-old defender played an influential role in Germany winning the World Cup last summer but he has been unable to reproduce that form for his club, who are facing relegation from the top flight just three years after reaching the Champions League final.

Hummels has made no secret of his ambition to move to a big-name club beyond his career at Dortmund and he admitted in January he was fully conscious of the interest from afar.

"It's not the case with any of us that this has been written for the first time," he said. "And with me rumours are always going around, but I'm still here.

"I'll let everything come to me. Everything else, I'm not thinking about."