Arsenal had a 2-0 win over Chelsea at the Emirates stadium but lost another important player as Hector Bellerin was stretched off with knee injury.
The Spaniard went down on the 70-minute mark following a challenge with Marcos Alonso.
Bellerin, who just returned from injury marked his return with an assist for Alexandre Lacazette’s opener.
However, Unai Emery has already planned how to replace Bellerin in the starting lineup as the Spaniard could be out until the end of the season.
Emery said: "We have Ainsley [Maitland-Niles], playing with good ‘pieces’. He played well today and can help us playing at right-back or right winger.
"Also [Stephan] Lichtsteiner is another player who can play there. We have the players. I don’t forget [Carl] Jenkinson who has played some matches and can be used if we need him."