Manchester United have reportedly already made an approach to sign Bayern Munich attacker Thomas Muller.
The German international has been linked with the former Premier League champions since Louis van Gaal was confirmed as David Moyes's official replacement earlier this month.
According to Bild, United, who are expected to have funds of around £200m to spend on players this summer, made an official approach for the 24-year-old two weeks ago, but were turned down by the Bundesliga outfit.
Muller has poured doubt over his own future at the Allianz Arena by claiming that he wants to hold talks with the club regarding his position in the team.
The German star had an inconsistent season under manager Pep Guardiola as he was regularly used as a substitute by the former Barcelona boss.