Manchester United's pursuit of Barcelona and Spain starlet Thiago Alacantra could be in serious trouble.

New Bayern Munich manager Pep Guardiola has said that he has asked the club to try and sign the midfielder.

Guardiola said he told his club that Thiago is the only players he wants and that "it's him or no one".

Thiago allegedly wants to leave Barcelona due to a lack of playing time as he finds himself behind Xavi, Andres Iniesta and Cesc Fabregas in the pecking order.

Meanwhile, Man United have said Nemanja Vidic's back injury is not serious.

The defender did not join the rest of the squad leaving for their tour of Asia, but may join up with them at a later stage.

"It's nothing serious," a club spokesperson told ManUtd.com. "Nemanja has a touch of sciatica [pain stemming from nerves in the back]".