And if that deal fails, United will make a £17million move for Ajax’s Daley Blind.

Hummels, Germany’s commanding centre-back, has been the top defensive target for new boss Louis van Gaal since the day he was appointed.

But Dortmund boss Jurgen Klopp insists Hummels, 25, is staying in the Bundesliga.

That means United will have to test that resolve with an offer of £30m.