Arsenal attacker Gabriel Martinelli was reportedly seen making his way through the mixed zone on crutches following the Gunners' 2-1 Premier League win over Brentford.
The Brazil international was unavailable for the clash with the Bees, having sustained a deep cut to the foot during Monday's 6-0 obliteration of Sheffield United at Bramall Lane.
As he was being helped off the field by the medical team in that game, Martinelli could not put any weight on his right foot, although Mikel Arteta said on Friday that the 22-year-old was on track to recover for the weekend.
However, Martinelli was ultimately omitted from the squad to face Thomas Frank's side, as Arteta explained to Sky Sports News: "Gabby (Gabriel Martinelli) has not made it. Unfortunately he has got a cut on his foot and we are trying to get him back."
When asked whether the South American's issue would be a short-term one, Arteta could afford a wry smile but refused to give too much away before Tuesday's Champions League clash with Porto.
According to football.london journalist Tom Canton, though, Martinelli was using crutches as he made his way through the mixed zone on Saturday, sparking fresh fears about his availability for midweek.
It is unclear whether Martinelli's crutches were indicative of a severe problem or simply being used as a precautionary measure, and Arteta will no doubt be pressed on the winger's fitness during his pre-Porto press conference.
The former Ituano starlet has failed to hit the same goalscoring heights he managed last season, but he still boasts a respectable eight strikes and five assists from 29 games across the Premier League and Champions League.
Martinelli was one of three absent players for Arsenal in Saturday's game, as Takehiro Tomiyasu failed to recover from his knock, while Jurrien Timber is still on the comeback trail after his ACL injury.
Oleksandr Zinchenko was fit enough to take his place on the bench, though, and Leandro Trossard benefitted from Martinelli's absence to start against the Bees, while Aaron Ramsdale came in for the ineligible David Raya in goal.
The Englishman had little to do at the start of the match, as Arteta's men deservedly went ahead through Declan Rice's header, but Ramsdale then made a horrendous error to gift Yoane Wissa a goal on the stroke of the break.
However, the 25-year-old enjoyed a redemption tale in the second half with two crucial saves, before Kai Havertz's 86th-minute winner sent Arsenal to the top of the Premier League over Liverpool and Manchester City.
The Gunners have a one-point advantage over the Reds and a two-point lead over Man City, and owing to their superior goal difference, they will retain first place if their two title rivals play out a draw at Anfield on Sunday afternoon.
Arteta's men host Porto in the second leg of their Champions League last-16 tie on Tuesday aiming to reverse a 1-0 deficit from the first encounter, where Galeno earned the Portuguese side a shock win with an injury-time wonder strike.
