Manchester United are monitoring Thomas Muller's situation at Bayern Munich. The Sunday Mirror says Muller became involved in a touchline bust-up with Pep Guardiola after being substituted in Bayern Munich's 3-0 Champions League humiliation at Barcelona on Wednesday.

And that has prompted United to try again to land the 25-year-old after two attempts to sign him inside the last year.

Louis van Gaal wanted to sanction a £40million bid for Muller on his arrival at Old Trafford after handing the forward his Bayern debut during his time in charge at the Allianz Arena.

Muller was immediately handed a new four-year contract, but that didn't stop United from making another enquiry in January.