Bayern Munich star Thomas Muller says he cannot guarantee he will spend the rest of his career at the club, although he insists he is happy at the Allianz Arena.

The 28-year-old has enjoyed a resurgence in form under Jupp Heynckes and registered a goal and two assists in the 4-0 Bundesliga win over Freiburg on Sunday.

Muller, who has spent his whole career with the German champions, admitted last September to being tempted by an offer from Manchester United in 2015, when former Bayern boss Louis van Gaal was in charge at Old Trafford.

And although he has no plans to leave at present, he concedes his circumstances could change.

"It's hard to look three or four years into the future," he told Sport1. "If things are going well, why should I want to leave?

"But you never know what will happen in the next few years. What are my capabilities? How are the conditions? Do I have the confidence of the coach, or not?"

Muller stressed, however, that he does not believe any player is being sincere when they say they have always dreamed of playing in a specific country.

"You have to show me who really had that dream," he said. "Normally, there's always a mixture of sporting and financial perspectives.

"Sometimes the whole package makes you decide on a foreign country, and sometimes not. But nobody can tell me that have had it planned for their whole career. 

"Very short-term things, like your private life, are at play in there."