The Germany international is highly regarded by David Moyes and could be a primary summer target as the Scot looks to rebuild his squad after a disappointing season
The Germany international, who scored a stunning opening goal in his club's Champions League victory over Arsenal, was strongly linked with a January move to Old Trafford, given the 24-year-old's contract with his Bavarian employers is set to expire in 2015.
With talks over a new deal at the Allianz Arena continuing to stall, his brother, who plays for Werder Bremen, has now revealed that the siblings have talked about a potential switch to the Premier League champions.
Felix told Sky Germany: "We have already talked about [Toni potentially moving to Manchester United].
"Manchester has been the team of my dreams since I was a child. However, I don't give him any advice.
"He will take a good decision for himself. There are worse situations than having to decide something like that."
Goal understands that Moyes is set to be handed a £100 million-plus (€120m) transfer kitty in the summer as he looks to rebuild his squad following what has thus far proved a disappointing 2013-14 campaign for the English champions.