Cristiano Ronaldo headed down the Old Trafford tunnel towards the end of Wednesday's 2-0 victory over Tottenham, having watched the outstanding team performance as an unused substitute.
In what was undoubtedly the best performance of the Erik ten Hag era to date, United were emphatic in everything they did as goals from Fred and Bruno Fernandes secured a victory which could have been far more humiliating for Spurs had it not been for a sensational showing from Hugo Lloris.
For 89 minutes, it was the perfect evening for United but the spotlight turned towards Ronaldo late in the game as he was spotted heading down the tunnel by himself, failing to see out the victory alongside the rest of the substitutes.
Two minutes earlier, Ronaldo had been warming up but did not enter the fray as Ten Hag opted to introduce Anthony Elanga and Christian Eriksen instead.
A visibly frustrated Ronaldo headed for the tunnel soon after, with no explanation given for his early departure.
"I will deal with that tomorrow," Ten Hag told Prime Video when asked about Ronaldo's departure.
It was the second time in the last four Premier League games that Ronaldo was not called on from the bench, with Ten Hag declining to introduce the Portugal international in the 6-3 drubbing at the hands of Manchester City out of 'respect' for his career.