Respected Spanish journalist Guillem Balague has claimed that Manchester City are playing 'a risky game' in their pursuit of Arsenal attacker Alexis Sanchez after news that Manchester United have joined the race.

City were expected to have a fairly free run at the Chilean international, but reports on Thursday have claimed that their bitter rivals United have made their interest apparent.

Balague has claimed that it will be up to Arsenal and Sanchez to decide what route to take, but City's unwillingness to offer more than £20m could put United in the driving seat.

"On Sanchez. After both Manchester clubs made offer, all up to Arsenal and player," Balague tweeted.

"Right now, City don't want to offer more than £20m and are convinced player wants to be with Pep [Guardiola], so will wait to the summer otherwise. Risky strategy if United offer huge figures to both club/player."

Sanchez has turned down the chance to sign a new contract at Arsenal, and he will be a free agent at the end of June.