The 28-year-old has found first team football hard to come by of late, with Laurent Koscielny and Per Mertesacker the clear first choice pairing at centre back for Gunners boss Arsene Wenger. The former Ajax star had been strongly linked with a move to Premier League rivals United, but Arsenal/s reluctance to sell to a big rival means Vermaelen looks set to move to Spain with Barcelona.
The news is something of a blow to Red Devils boss Louis van Gaal, who had earmarked Vermaelen as the man to improve his thin United defence. The key to their interest in Vermaelen was that his ability to play at both centre back and left back fits perfectly in van Gaal's 3-4-1-2 system, with centre backs often flowing out to play full back.
With that in mind, here are some players who fit the same bill that United could look to target before the transfer deadline in less than a month's time.
Angelo Ogbonna, Juventus
With the likes of Giorgio Chiellini, Andrea Barzagli and Leanardo Bonucci ahead of him in the pecking order, 26-year-old Ogbonna is seemingly out of the picture in Turin. With power, pace and above average technical ability, Ogbonna could be a viable solution for United given that the former Torino star has already been linked with Arsenal. An exit seems inevitable, and van Gaal could land Ogbonna for a similar price as Vermaelen.
Stefan Radu, Lazio
Earlier this summer, United were linked with a swoop to sign Lazio's Romanian international Radu. With plenty of experience at centre back and left back, he's shown throughout his career that he's capable both going forward and defensively. Compared to compatriot Christian Chivu, Radu has the technical and physical attributes to be a good signing for United – even if he isn't quite the big name that fans want to see.
Yaroslav Rakitskiy, Shakhtar Donetsk
One of the most underrated defenders in Europe, Rakitskiy has been the key of the Shakhtar defence for some time now. Rakitskiy is confident in possession and loves to get forward, but is equally adept defensively too. Still young, Rakitskiy has been regularly linked with a move to Barcelona, and whilst it's unlikely that United would try to sign the 25-year-old, he certainly fits the profile for van Gaal.
Marcos Rojo, Sporting Lisbon
The Argentine World Cup star has been linked with a whole host of Premier League sides, including Arsenal, Chelsea and Liverpool. A centre back for Sporting Lisbon and a left back for his country, Rojo's stock has increased exponentially over the past 12 months having impressed in Portugal and Brazil this summer. With plenty of untapped potential, Rojo could be the ideal option for van Gaal.
Jan Vertonghen, Tottenham Hotspur
The biggest name of the list is Spurs star Vertonghen, who has the same Ajax upbringing as Vermaelen and van Gaal. Barcelona were strongly linked with a £20m move to sign the Belgian international earlier this summer, and United may need to spend more than that if they would ever tempt their Premier League rivals into a sale. For the role United have, Vertonghen is the perfect fit.