The 34-year-old left the Gunners during the summer after going on strike to force the club to sell him to Bordeaux.
His first concerns centred around Emery’s delay over confirming he would remain as Arsenal captain following the Spaniard’s arrival.
Emery took until mid-August to make his decision, which was then followed by the departure of the club’s former chief executive Ivan Gazidis, causing doubt over the renewal of Koscielny’s contract.
A new deal had already been discussed, with the potential for Koscielny to even stay on as part of Arsenal’s coaching staff after his playing days.
But Gazidis’s departure left Koscielny uncertain on his future at the club and feeling undervalued.
This only increased on his return from a serious achilles injury in December, which Koscielny feels was mismanaged by Emery.
Under Arsene Wenger the defender’s schedule was adapted to deal with his ongoing bout of achilles tendinopathy, to avoid him having to undergo pain-killing injections to get him through matches.
His subsequent rupture was not caused by his workload, and was more down to misfortune, but his recovery placed huge strain on his aging body as Emery put significant pressure on the player to perform.
After returning to first-team action against Qarabag in the Europa League, having been out for seven months, Koscielny was then involved in the defeat to Southampton just three days later.
He was then selected to play in an FA Cup third round fixture away at Blackpool, just four days after completing a full 90 minutes against Fulham , while the majority of regular Arsenal first-teamers were rested.
Koscielny withdrew from the game with a back injury just before kick-off, but later featured in nine matches in six weeks which took their toll, including the Europa League final hammering at the hands of Chelsea .
Aware of interest from China and France, Koscielny refused to go on Arsenal’s pre-season tour of the USA, eventually forcing Arsenal to sell him to Bordeaux for £5 million.