Unai Emery fears that Hector Bellerin suffered a serious knee injury during Arsenal's 2-0 win over Chelsea.
Arsenal's superb London derby win was tainted as full-back Bellerin was stretchered off with a knee injury.
First-half goals from Alexandre Lacazette and Laurent Koscielny gave the Gunners victory, and put them back within three points of the Premier League top four.
However, they lost Bellerin after 72 minutes after he went down without contact from a Chelsea player, appearing to twist his knee.
Another injury would be a cruel blow to the 23-year-old, who only returned from a calf strain in the defeat to West Ham last weekend, and was making his first Premier League start since the loss against Southampton on December 16.
While the Gunners will have to wait for a more thorough assessment, Emery confirmed that their first impressions were not good.
"We are going to wait tomorrow but it is his knee and the first prediction is that it can be an important injury but tomorrow or Monday the doctor will confirm,” the Spaniard said.
“I hope not but it is not positive, our first impression.”
There are just under two weeks of the January window left should Arsenal want to consider replacing Bellerin.
However, with Ainsley Maitland-Niles, Stephan Lichtsteiner and Carl Jenkinson having all featured at right back this season, as well as recent admissions that the club can only realistically afford to bring in players on loan, Emery’s transfer plans will not be impacted.
“We have Ainsley, he is playing with good pieces, he played well today and he can help us playing like a right back or right winger and also Lichtsteiner is another player and I think we have players,” he added.
“Don’t forget Jenkinson, he is with us he played some matches and if we need he is okay to help us.”
Arsenal’s next fixture is Friday night’s FA Cup fourth-round clash with Manchester United at the Emirates.
