Manchester United could use defender Chris Smalling as a sweetener in a deal taking Arsenal captain Thomas Vermaelen to Old Trafford.

Louis Van Gaal is looking to strengthen United's defence following the departures of Nemanja Vidic, Rio Ferdinand and Juventus-bound Patrice Evra.

The Dutchman, whose first day at United saw players complete a double training session, regards the Belgian international highly because of his ability to play centre-back and left-back.

The 28-year-old has just one year left on his contract and United are keen to snatch the north London club's captain for the second time in two years after signing Robin Van Persie in 2012, reported the Evening Standard.

Chris Smalling
Chris Smalling enjoyed a promising start for United but his form has dipped Getty

Vermaelen has played 150 times for the Gunners and has won 47 caps for Belgium but found himself relegated to the substitutes' bench last season as Arsene Wenger built a defensive partnership between Per Mertesacker and Laurent Koscielny.

Even though the defender has just 12 months left on his Arsenal contract, Wenger may hold the upper hand in negotiations, knowing that United have just Luke Shaw as a recognised left-back, after Evra and Alexander Buttner's exit, and lack experience at the heart of their defence.

Tom Cleverley has also been highlighted as a possible makeweight but after the capture of Alexis Sanchez and with a bid for Real Madrid cast-off Sami Khedira reportedly in the pipeline, it is unlikely Wenger will see any value in taking the England midfielder off United's books.

Meanwhile, United new boy Ander Herrera joined fellow new signing Luke Shaw at United's Aon Training Complex where Van Gaal was introduced to his first team squad.

A morning training session was followed by a team lunch where Van Gaal met his coaches and youth team before players headed back to the training pitches for 5.30pm.