The France international returned from a serious injury last month when the 33-year-old featured in a 1-0 win against Qarabag in the Europa League at The Emirates.
Koscielny was sidelined over six months after the Arsenal skipper suffered the injury during their 1-0 loss to Atletico Madrid in the second leg of their Europa League semi-final in April.
The French centre-half was expected to start Arsenal’s clash against Blackpool at Bloomfield Road on Saturday but Koscielny was withdrawn before the FA Cup clash.
English defender Carl Jenkinson replaced Koscielny as Arsenal eased to a 3-0 win over the Championship side to book their place in the next round of the competition.
Speaking at his post-match media conference at Bloomfield Road, Arsenal manager Emery provided an update on Koscielny’s fitness after his absence in the 3-0 win at Blackpool.
“Yes [it’s a back problem],” Emery told his news conference after the game. “I hope it’s not bad. He has one week to rest and to work, thinking about the next match against West Ham.
“I hope he’s going to be OK for the next matches but before the match, he felt some pain in his back. We decided it was better for him to not play.
“At the moment, with our problems at centre back, it meant we were able to look at different players in different positions.”
Arsenal signed Borussia Dortmund centre-half Socrates Papastathopoulos and Juventus full-back Stephan Lichtsteiner in the summer transfer window to improve Emery’s defence.
The Gunners have conceded 31 times in 21 games in the Premier League this season, highlighting that Emery still has work to do to transform Arsenal into a cohesive defensive unit.
Arsenal are in fifth place in the Premier League table.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news