By Pete O'Rourke, Transfer Correspondent

5th Oct, 2019 | 8:00am

Exclusive: Arsenal line up transfer missions for West Ham 22-yr-old ahead of January

Arsenal are keeping close tabs on West Ham defender Issa Diop, Football Insider understands.

The Londoners are assessing potential centre-back options as they look to strengthen their brittle back line.

An Arsenal source has told Football Insider that the club have lined up regular transfer missions to assess the Diop, 22, as they look at long-term centre-back targets.

West Ham spent £22million on the 6ft 4in defender in the summer of 2018 and his value has escalated during his time in the Premier League.

Diop is now fully established as not only a first choice but also the outstanding centre-back in Manuel Pellegrini’s side.

Described last season as a “monster” by Jose Mourinho, he has started all seven of the club’s Premier League matches this season as well as both their League Cup game.

This comes after he made 33 league starts among 38 appearances in all competitions in his debut campaign after signing from Toulouse.

Arsenal’s first choice centre-back pairing this season have been surprise summer signing David Luiz and Sokratis, although neither has been especially convincing.

Unai Emery’s side have showed they are willing to spend big money on players they think can improve their team.

They forked out a club-record £72million on Nicolas Pepe in the summer as well as £27million for William Saliba, £25million for Kieran Tierney, £8million for Luiz and £6million for Gabriel Martinelli.

In other West Ham news, it can be REVEALED that the Hammers are ready to sell international in January with multiple clubs keen on signing him.