The Belgian international has fallen down the pecking order at the Emirates Stadium, and has been linked with a move away from north London.
Vermaelen is still Arsenal club captain, but made just 14 league appearances last term having been replaced by Per Mertesacker alongside Laurent Koscielny at the heart of the Gunners' defence.
Fiorentina were said to be in the race for the 28-year-old's services, however according to the Daily Mail, Manchester United are now primed to make a move for him.
The paper claim that the Red Devils were interested in making a move in January while David Moyes was still in charge, and could now rekindle their interest with Louis van Gaal at the helm.
Manchester United have lost both Nemanja Vidic and Rio Ferdinand which leaves them looking short at the back, and are said to view him as the ideal addition to their squad. Given that the defender is out of contract next summer could force Arsenal to sell up if he won't commit his future to the club, while Manchester United will be confident of securing a cut-price deal.
Any deal is unlikely to be completed until after the World Cup finishes.