Arsenal face another period of uncertainty as they wait to see how bad Laurent Koscielny’s back injury is.

The club captain was named in the starting lineup for the FA Cup game against Blackpool on Saturday but removed himself from the warmup when he felt pain in his back.

Speaking to the press after the game, Unai Emery could not give much of an update. “Yes [it’s a back problem]. 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. Today that was Lichtsteiner, who played with very good commitment and concentration to help us at centre back with Sokratis.”

Speaking recently, Kos admitted that he had been rushed back by the club due to the injury crisis Emery’s men were facing at the back. “It’s going very well,” the Arsenal captain said after the game against Fulham. “I do not have any pain.

“After that, my return was a bit hasty with the injuries in the group, so I had to follow up a bit physically hard, but I feel good.

“It’s the pace I miss,” Koscielny added. “It’s a little harder to tie up every three days, I’m trying to be careful not to hurt myself and be out for weeks. What it takes to be at the disposal of the coach, he makes me play [some] games, others I attack from the bench.”

Emery alluded to this when he spoke to the BBC. “With Laurent, we need to be calm with some moments in the training sessions because we are pushing him to play a lot of matches after his big injury,” he said.

“So maybe he needs some time not playing, but we had another player with big commitment to play in a different position today, Stephan Lichtsteiner.

“Laurent said he could not play the match but now we have one week to rest before the next game [away to West Ham in the Premier League] and hopefully he will be okay.”

Although not definitively proven, there does seem to be a link with Achilles’s problems and sciatica, the longest nerve in the body that runs from the lower back down the back of the leg.

Koscielny has been sidelined twice before with back problems, once in 2010/11 when he missed four games and 24 days, then again in 2015/16 when he was out for just seven days.