He was linked with a deadline-day transfer to Manchester United and has found himself on the outside looking in at City, having been left on the bench for every Premier League game so far.
That lack of involvement is beginning to raise questions over his long-term place in the squad.
Milan are one club who could potentially offer Ait-Nouri an escape route should his situation at the Etihad fail to improve.
Sources have indicated that the Serie A giants are monitoring the left-back market ahead of next year, with Ait-Nouri one of the Premier League options on their radar as they begin early planning for 2027.
It is still early in the process, but his current situation makes him an increasingly interesting player to watch.
The proposed loan switch to Man Utd never developed into a serious possibility - partly because of the rivalry and history between United and City making such a deal complicated, but the interest was notable given the player's circumstances.
Now, with 25-year-old Ait-Nouri struggling to establish himself in Enzo Maresca's team, the question is whether that situation could eventually force the issue.
For Milan, it could represent an opportunity.
They have Pervis Estupinan as a current option at left wing-back, but his own future is not necessarily guaranteed. There was talk during the summer of a potential return to the Premier League for the Ecuador international, who previously played for Brighton and was linked with Aston Villa.
He remains involved at Milan and is trusted for now, but Milan are understood to be assessing the position longer term.
Flashscore understands that Milan also have Fulham's Antonee Robinson on their radar as a name of interest as they assess potential solutions.
The United States international has been regularly linked with a move away from Fulham in recent seasons, although nothing has materialised. Milan are understood to be monitoring how his season develops, with the belief that his attributes could translate well to Serie A.
Fulham's difficult start could also make Robinson's situation one to watch.
They have lost their opening three Premier League games of the season, and Milan will be interested to see whether the club's fortunes improve and how Robinson performs as the campaign progresses.
