Benfica sports chief Rui Costa says Axel Witsel has the ability to play for Europe's biggest clubs.

The Belgium international is being tracked by Manchester United, Chelsea and Manchester City.

Rui Costa told Calciomercato.it: "He's one of the few young men of a high level ready to compete at a top club, although I hope he can continue with us for a long time.

"In the event of his sale, I hope he will move to a club that allows him to continue on his development path.

"We are proud of having come upon him before other clubs of a high level. Whoever will take him away from Benfica will certainly have to put in place a great investment."