Cristiano Ronaldo headed straight down the tunnel at the end of Manchester United's 1-1 draw at Chelsea on Sunday without even a glance over his shoulder to his teammates or the supporters who so readily chant his name.
The former Real Madrid and Juventus forward doesn't tend to hang around on the pitch once the final whistle has blown, but his sharp exit at Stamford Bridge seemed more pointed than usual. It certainly wasn't due to fatigue, considering he had only been involved for 26 minutes after replacing goal scorer Jadon Sancho as a second-half substitute.
Perhaps it was the realisation that, once interim manager Ralf Rangnick arrives to take charge at Old Trafford, he may have to get used to the kind of experience that he endured at Chelsea on Sunday afternoon.
Unless Rangnick changes his entire approach to the game, United's tactics and formation under the new boss will be very similar to those deployed by caretaker-manager Michael Carrick against Thomas Tuchel's team: They will be more solid in midfield and the forwards will be expected to press high with energy and be the first line of defence at all times. And therein lies the problem for Ronaldo. He is many things, including an incredible goal scorer, but he does not have the energy, or seemingly the appetite, to do the job that Rangnick expects of his forwards and which Sancho, Marcus Rashford and Bruno Fernandes produced on Sunday.
"I thought the front three, Marcus, Jadon and Bruno, did a great job of knowing when to press and when to drop off," Carrick said after the game.
The big question that Rangnick must answer quickly is whether he will compromise his philosophy to accommodate United's star player or if Ronaldo must now accept a different role -- one that he may not like -- as an impact substitute.
Ronaldo will never be content to spend more time on the bench than the field of play. Even though he is approaching his 37th birthday in February, he remains one of the most driven and determined footballers in the game. It's simply not in his make-up to accept a bit-part role, even though Carrick said before kickoff against the Premier League leaders that Ronaldo did not protest against his surprise demotion.
"I have had a good chat with Cristiano," Carrick said. "And he was great."
With United due to face Arsenal at Old Trafford on Thursday, followed by another home game against Crystal Palace next Sunday, Ronaldo's omission against Chelsea may have been nothing more than game management to ensure that the Portugal international is fresh for those two fixtures.
Having made little or no impact during the recent defeats against Liverpool and Manchester City, which played a big part in Ole Gunnar Solskjaer's dismissal as manager, it made sense to leave Ronaldo out against the European champions. Whether it was Carrick or Rangnick who made the decision is unclear, although Carrick insisted that Rangnick was not involved in team selection for the Chelsea game. "That wasn't the case, no," Carrick said.
But despite his failure to make an impact against Liverpool and City, Ronaldo remains United's leading goal scorer by some distance this season. With 10 goals in all competitions, he has scored more than twice as many as Fernandes and Mason Greenwood, who are joint-second on the list with four apiece.
So planning ahead without Ronaldo will be a gamble for Rangnick. Yes, his work rate is not what the German would normally demand of his forwards, but his goals have rescued United more than once this season, so if his involvement diminishes under the new coach, somebody else will have to step up significantly.
When they signed Ronaldo from Juventus in August, there was always a danger that United would become over-reliant on a player who has scored 799 career goals for club and country. Having him back at the club, after he initially left United for Real Madrid in 2009, was regarded as an opportunity that they couldn't refuse and it is an endless debate as to whether he has been good for the team or detrimental.
But Rangnick represents the here and now, and Ronaldo will be judged on what he can and can't do.
When Fabio Capello took charge of England in 2008, he quickly made it clear that he could not, or would not, find a place for Michael Owen in his team, despite the forward being just 28 at the time and having scored 41 goals in 88 appearances prior to Capello's appointment as manager. Capello regarded Owen as being no more than a goal scorer and a player incapable of bringing enough to the team, beyond his goals, to justify his inclusion. He selected him just once, as a substitute, before overlooking him for the rest of his time in charge.
Ronaldo may turn out to be Rangnick's version of Owen at United -- a player with an outstanding goals record but not much else. And if that proves to be the case, Ronaldo's return to Old Trafford is likely to be short-lived because he didn't sign up for a second spell at United simply to watch it all unfold from the bench.