Former Chelsea midfielder Michael Ballack can't believe Manchester United allowed Paul Pogba to leave.

Pogba will start for Juventus in the Champions League final tonight against Barcelona.

"It seems like it was a mistake from Manchester [United] to let him go," Ballack told Sky Sports.

"He has this desire. His physical ability is there. He also has the nous to read situations, and to be in the box to score goals.

"He can still improve that, and if he does he can be an outstanding player."