Cristiano Ronaldo is trashing his legacy at Manchester United and making it even more difficult for himself to find an escape route from Old Trafford.

Following his latest display of indiscipline when storming off to the locker room as an unused substitute before the end of Wednesday's 2-0 win against Tottenham Hotspur in the Premier League -- with sources telling ESPN that he left the stadium before the final whistle -- the 37-year-old is in danger of becoming more trouble than he is worth, both for United and any club that might still be interested in signing him.

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The former Real Madrid and Juventus forward silenced the doubters in his first season back at United last year -- he completed a €15 million move from Juve, having left United for Real in 2009 -- by scoring 24 goals in all competitions as the team endured its worst Premier League campaign.

Despite many critics suggesting that Ronaldo would upset the balance of Ole Gunnar Solskjaer's team, the Portugal international was at least able to point to his goal tally as proof that he delivered on the pitch while many of his teammates fell well below their expected standards. But all the negativity that Ronaldo was predicted to bring last season has now started to surface in his second year back at Old Trafford.

Ever since his associates made it clear in June that Ronaldo wanted to leave United for a team in the Champions League, he has become an unnecessary distraction at the club, constantly overshadowing the progress being made by the team under Erik ten Hag since the manager was appointed in the summer. Ronaldo missed the entire preseason tour of Asia and Australia, citing family reasons, and then angered Ten Hag by driving away from the stadium during the second half of the preseason friendly against Rayo Vallecano in July. Ten Hag described Ronaldo's actions that day as "unacceptable."

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Although Ten Hag has said publicly that he is keen to work with Ronaldo as part of his squad, sources have told ESPN that the former Ajax coach would not have objected to the player leaving Old Trafford this summer. Ten Hag is pragmatic about Ronaldo's qualities, and he is happy to have his goal threat in the squad but also realises that his global stature means that displays of petulance such as Wednesday's unauthorised early exit to the locker room become huge talking points.

To compound matters, Ronaldo's walk-off on Wednesday came just three days after he reacted with disdain to being substituted during Sunday's 0-0 draw at home to Newcastle United, shaking his head in a visible show of dissent at Ten Hag's decision to replace him with Marcus Rashford. On that occasion, Ten Hag said he understood a player of Ronaldo's calibre being unhappy at being substituted, but it was just another example of the effect that Ronaldo is having at Old Trafford.

The win against Tottenham was United's best display under Ten Hag and one of the team's most exciting performances since Sir Alex Ferguson retired in 2013, but you wouldn't think so because Ronaldo has ensured that the aftermath is all about him and his actions.

At his peak, Ronaldo was accustomed to dominating the spotlight for the right reasons, but he appears incapable of accepting that he is no longer the centre of attention at United. He has started just two Premier League games all season, making six appearances from the substitutes' bench. In total, he has amassed 340 minutes on the pitch in the league and contributed just one goal and one assist.

When scoring in the 2-1 win at Everton earlier this month, Ronaldo reminded us that he remains a clinical finisher of half-chances and is still United's best goal scorer, but he does not contribute enough when he is not hitting the back of the net. Ten Hag has been bold enough to acknowledge that and select players more capable of providing the work ethic that Ronaldo cannot, or will not, deliver.

Ten Hag has had to make a judgement call about Ronaldo and has decided to largely rely on him as a substitute. If Ronaldo had been prepared to accept his reduced status as he approaches his 38th birthday in February, it is a compromise that could have worked, but unfortunately for United and Ten Hag, he has been unable to adjust to his new reality.

Ronaldo is still the consummate professional when it comes to his own fitness and longevity, but he has now reached the stage of his career where he must accept he is now merely part of a team rather than the player who drives it.

It is an uncomfortable transition for any great player, but Ronaldo's behaviour is making it increasingly difficult for Ten Hag to trust him to do his bit for the team. He has become a problem that United can do without and a player whom the top clubs will want to avoid when the transfer window opens in January.

And having enjoyed such a remarkable and distinguished career, Ronaldo is now reaching the end by becoming an irritation and a distraction, and that will only damage his well-nurtured reputation.