Saka has been struggling with fitness issues over the last couple of weeks, after picking up knocks against Tottenham Hotspur and Bournemouth.
The England international appeared to shake off any fitness concerns to take his place in the side for Tuesday's Champions League meeting with Lens.
Saka provided the assist for Gabriel Jesus to open the scoring, before Lens restored parity through Adrien Thomasson.
Unfortunately for Arsenal, Saka was unable to make it to half time after he picked up an injury issue and had to be replaced by Fabio Vieira in the 34th minute.
In Saka's absence, the Gunners went on to lose 2-1 to their French opponents following a second-half winner from Elye Wahi.
While Saka sustained a suspected hamstring tweak, Mikel Arteta defended his decision to start the 22-year-old in France.
According to the Daily Mail, Saka is a doubt for Sunday's top-of-the-table clash with Man City at the Emirates Stadium.
The Englishman is set to undergo further assessment on Thursday after having an initial scan on the injury on Wednesday.
The report claims that Saka's chances of being involved against the Premier League champions are being assessed on a day-by-day basis.
England manager Gareth Southgate has also been made aware of Saka's fitness status, as he prepares to announce his latest squad on Thursday.
Southgate will be hoping to have Saka available for a friendly with Australia and a Euro 2024 qualifier against Italy.
The winger has scored four goals in England's qualifying campaign, including a hat-trick in June's 7-0 thrashing of North Macedonia.
Meanwhile, Saka has helped Arsenal make an unbeaten start to their Premier League campaign, scoring four goals and providing two assists in seven league matches.