Manchester United have reportedly made contact with the representatives of Arsenal defender Hector Bellerin as they begin their search for a new long-term option at right-back.

Antonio Valencia, 32, has reigned as United's starting option on the right side of defence in recent years, but Ciaran Kelly of the Manchester Evening News wrote that Bellerin is being monitored as a potential successor.

Kelly added the Red Devils are "in regular contact" with Bellerin's people and have requested they be kept up to date on the Spaniard's situation, with some reports of unrest emerging at the Emirates Stadium this season.

Jack De Menezes of The Independent detailed Bellerin's falling out with supporters' channel ArsenalFanTV following some disappointing displays this term, although Charles Watts of Football.London has said he should be more revered at the club:

It wasn't long ago Barcelona academy product Bellerin was being talked about as arguably the best right-back in the Premier League, but his production has taken a hit in recent months.

That being said, Bellerin remains only 22 years of age, and Watts explained why he felt the Spain international deserves a priority place in the Arsenal squad of years to come:

Valencia remains in good form at Old Trafford, but it's expected his pace, arguably the greatest of all his attributes, will soon start to decline if it hasn't begun to already.

The Ecuadorian turns 33 in August, and WhoScored.com recently compared his figures this season to that of another emerging Premier League full-back, where he came off worse in almost every facet:

Bellerin has the potential shelf life to last for another decade at the top level, and Kelly wrote that Luke Shaw's return to form on the left flank has left United able to invest more heavily on the opposite side of defence.

United also have Timothy Fosu-Mensah—on loan at Crystal Palace—coming through their ranks, a player Manchester City star Leroy Sane recently hailed as his toughest opponent, per the Mirror's Mark Jones (h/t Full Time Devils):

Axel Tuanzebe is another United starlet capable of playing at right-back, although it's expected the club will concentrate on developing the Aston Villa loanee into a central defender.

United boss Jose Mourinho has signed specialist players in specific roles at Old Trafford thus far, but Arsenal may not take to the idea of letting another asset leave for the Red Devils after Alexis Sanchez did so in January.