A quick and technically able footballer capable of playing all across the midfield as well as both full back positions, Alaba has established himself as Bayern's first-choice on the left side of defence during the German club's run to the Champions League final.
United regard the Austria international as a possible long-term successor to Patrice Evra.
There is no question of Evra, who is highly valued by Sir Alex Ferguson, being permitted to leave Old Trafford. The United manager, however, would like to lessen the demands on a captain who started five more Premier League fixtures than any of his teammates during a during a season in which he had to cope with both the death of his brother and the Luis Suarez racism case.
Alaba, who turns 20 next month, is both the youngest man to play a competitive match for Bayern and a full international for Austria.
Although he has been in Munich since joining from Austria Vienna in 2008, an opportunity to hold down a starting berth at Bayern only presented itself in February because of enforced absences in defence.
Suspended for Saturday's final against Chelsea after collecting a yellow card in the semi-final victory over Real Madrid, Alaba is contracted to Bayern until 2015 after signing a two-year extension last June.
While ideally matched to United's strategy of recruiting younger players, he is likely to prove difficult to extract from a club that rarely permits its most talented individuals to leave.
United intend to loan Fabio da Silva, possibly to another Premier League club, to make room next season for a new left-back. They have also told Michael Owen that his contract will not be renewed for next season amid interest in the former England striker from promoted Reading.
"The manager informed me after our testimonial match on Tuesday that the club would not be offering me a new contract," said Owen on Thursday.
"I have loved every minute of the three years I have spent at such a fantastic club. I now plan to have a short holiday during which I will contemplate my next move.
"I would like to play another couple of years and play more regular. I don't think the Championship would be an option.
"I certainly feel I can play in the top level. We will wait to see where that is.
"If it's not in the Premier League I may look further afield, but I don't think I will be going into the Championship."
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