The England winger was named in the Gunners’ starting lineup for a key Premier League match at Elland Road, only to suffer what was reported to be a left hip issue during the warm-up.
He left the warm-up early along with a physio and headed back down the tunnel, replaced on the right flank for the game by Noni Madueke.
Asked for an update on Saka after an emphatic 4-0 win for his side in which Madueke starred, Arsenal boss Arteta told reporters: “Saka, he had a little niggle [in the warm-up].
“He wasn't comfortable to start the game so immediately we made the decision to make the change and bring Noni in.”