Former Manchester United midfielder Owen Hargreaves has warned his old club that they should not sign Mats Hummels because he is too slow and cannot defend.
The Borussia Dortmund centre-back has been linked with a move to Old Trafford for some time, and it is expected that the Red Devils will make an approach to sign him during the summer.
However, Hargreaves believes that Hummels is not the right man to reinforce United's defence.
"He's a super, super ball-playing centre-back but I don't think he can defend, he's too slow," Hargreaves told BT Sport.
"He's Franz Beckenbauer, the new version, a super passer but I think that if I'm Manchester United I want Vidic, I want Kompany. I think he's a nice football player, he's easy on the eye, but United need somebody physical, a presence.
"He's the captain of Borussia Dortmund, they're last in the Bundesliga. Is that the measuring stick for Manchester United? I'm not so sure."
Hummels has won 38 caps for Germany.