Arsenal are gearing up for one of the biggest squad overhauls in Arsene Wenger's 21-year reign.

The Gunners — led by newly appointed head of recruitment Sven Mislintat — have already started planning what will almost certainly be an extremely busy summer of incomings and outgoings.

As many as 10 first team players will head into the summer with their futures uncertain, and scouts are already working on their replacements.

Mainz's Abdou Diallo (right) is one of two central defenders being lined-up to join Arsenal

Nice midfielder Jean Michael Seri is also on the Gunners radar as part of the overhaul

Mislintat's knowledge of Germany, having worked with Borussia Dortmund prior to his arrival at Arsenal, has seen the club intensify their scouting resources in the Bundesliga.

Indeed, Sportsmail can reveal Mainz's Abdou Diallo and Wolfsburg's Ohis Felix Uduokhai are two central defenders already earmarked to replace club captain Per Mertesacker, who will join Arsenal's academy in a coaching capacity at the end of the season.

Nice midfielder Jean Michael Seri is also on the club's radar. Intriguingly, Barcelona failed with a £36million offer for the Ivory Coast international last summer in a swoop that was fronted by Raul Sanllehi - who has since joined Arsenal in the role of head of football relations.

Alexis Sanchez is almost certain to leave Arsenal in either next month's transfer window or on a free at the end of the season.

Arsenal, it is understood, are keen to offload Sanchez in January with sources claiming the Chilean is proving a disruptive figure off the field.

Manchester City and Paris Saint-Germain are both set to bid for Alexis Sanchez next month

Midifielder Jack Wilshere has six months left on his current deal and is free to leave in June

Manchester City and Paris Saint-Germain are both set to bid for Sanchez next month.

The Gunners are trying to prevent Mesut Ozil from running down his deal, but if the club fail to agree an extension the Germany star will also leave for nothing in the summer.

Lyon's Nabil Fekir, who has impressed Arsenal's French-based scout Gilles Grimandi, is a candidate to replace Ozil if he goes.

The club are trying to convince Danny Welbeck and Aaron Ramsey to sign new long-term deals in the coming months as they enter the final year of their respective contracts.

The club is trying to convince Danny Welbeck (centre) to sign a new long-term deal

Aaron Ramsey (right) is another player the Gunners want to tie down to a long-term contract

However, new deals for the pair are far from certain meaning the club could be forced to listen to offers in the summer to not risk losing the duo for nothing in 2019.

There are major fears over whether Santi Cazorla will ever play again — let alone for Arsenal — following his latest setback from an Achilles injury. The Spaniard's existing deal expires in the summer.

Jack Wilshere, who is keen to stay, has six months left on his current deal but hasn't even been formally approached about an extension leaving him free to leave in June.

There are also doubts over the long-term futures of Olivier Giroud and Theo Walcott, who are growing frustrated at their lack of regular first team opportunities.

There are doubts over the future of Theo Walcott, who is on the fringes of the first team

Walcott is already on the radar of Everton and Southampton. Mathieu Debuchy is also set to leave the club in the next two transfer windows.

All that points to one of the most extensive recruitment drives in Wenger's reign.

Mislintat and Sanllehi, who will officially start work on February 1, were both appointed well in advance of the summer to ensure they could make early progress on the summer rebuilding job.

In his role as manager, Wenger is used to having the final decision on the club's transfer policy.

But while Wenger retains the role of boss, it remains to be seen whether his power is diluted due to the new administrative arrivals.