Manchester United fear a challenge from Chelsea in their bid for Atletico Madrid star Antoine Griezmann.

The Sunday Mirror says Griezmann is the main priority signing for United boss Jose Mourinho.

But he could lock horns with Chelsea in the transfer market if Diego Costa does quit the Bridge.

For if he leaves Chelsea will be rivals to United in the chase for French attacker Griezmann who is set to be football's most wanted man next summer.

With the long term United future of skipper Wayne Rooney certain to be an on-going issue, Mourinho believes Griezmann would enhance his striking options – even at the whopping £75 million Madrid would demand for the star.