Arsenal manager Arsene Wenger says defenders Per Mertesacker and Laurent Koscielny could be ruled out of Saturday's away game against Newcastle.
The pair did not feature in Monday's goalless draw against Liverpool as they were replaced by Calum Chambers and Gabriel Paulista in the heart of the Arsenal defence.
"Per Mertesacker is sick," Wenger told reporters.
"How long will that sickness take? I don't know. [Laurent] Koscielny has a back problem. Having said that, our two centre backs played well in the second half.
"[Calum] Chambers and Gabriel [Paulista] do not have the experience of playing together, they've come in from one day into the next, but overall we didn't concede.
"Petr Cech saved us two or three times in the first half. In the second half I think we should've won the game. We were a bit unlucky, we lacked a bit physically and collectively to finish what we started.
"Our game is still not fluent enough in the final third, and that's why we didn't score.
"The West Ham game left a trace in our heads, and it was important tonight not to lose because you could see that was a shock for us and it was important for us to get that game out of our system."
The Gunners struggled to cope with the pace and quality of the Liverpool midfield in the first half but the Frenchman says there is no need to panic ahead of the last week of the transfer window.
"[If we need more powerful midfielders?] Everybody has their opinion and everybody is entitled to have an opinion," he said.
"I could prove to you that it's not necessarily right, but let's not go into that debate tonight. When you don't win, you're wrong and people always find reasons why. Are they the good reasons? I think I have enough experience and intelligence to know when it's right and when it's wrong.
"[And] that story [about Karim Benzema is dead] but it has always been created every week, again and again.
"We do not master that situation. When the player has a contract it's the club who owns the contract who decides that and I have said that many times.
"We want to master the situation of the players who are under contract with us. We had Wilshere and Welbeck out tonight, Alexis is not completely at his best. We know that we can score goals and we will score goals again."