Cristiano Ronaldo has fired a warning to Man Utd star Edinson Cavani

Cristiano Ronaldo and Edinson Cavani are team-mates at Manchester United.

Cristiano Ronaldo is back at Manchester United. Haven't you heard? He was back amongst the goals, too, blitzing Newcastle at Old Trafford on Saturday. And his performance against Steve Bruce's side is a big warning to Edinson Cavani.

Manchester United weren't at their best against Newcastle on Saturday afternoon.

But that didn't matter by the end of the game, with Ronaldo stealing the headlines on his first match in red for 12 years.

Bruno Fernandes and Jesse Lingard also struck to give Ole Gunnar Solskjaer's side all three points.

But make no mistake about it. This was Ronaldo's afternoon.

And his electric performance suggests Cavani may struggle for regular starts during what is expected to be his final season at the club.

Last season, the Uruguay international fared well. Particularly at the end of the campaign, when Anthony Martial was out injured.

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Cristiano Ronaldo is back at Man Utd and eager to win trophies

A modest return of 17 goals meant he broke the No 7 curse that has plagued the club ever since Ronaldo's exit back in 2009.

But with United preferring to play with just one striker under Ole Gunnar Solskjaer, it's now hard to see where he fits in.

Ronaldo is now a striker, having originally been a winger during his first stint with the Red Devils.

Cavani did play out wide at Paris Saint-Germain to accommodate Zlatan Ibrahimovic but the veteran was never really a fan of that position.

Therefore, it's feasible he'll now spend most of the campaign watching on from the sidelines.

Solskjaer also has Mason Greenwood at his disposal, a player he's regularly tipped to be a centre-forward in the future.

So where Cavani goes from here remains to be seen.

Ronaldo is now United's player but the club must also dance to his tune to keep him happy, or face a backlash.

After all, the likes of Jose Mourinho and Rafa Benitez were never able to recover after getting on his bad side during his time at Real Madrid.

And given Ronaldo's huge appetite to play, Solskjaer may find himself having no choice but to start him in every game.

Take Tuesday's Champions League clash with FC Young Boys, for example.

Without Ronaldo, United are still expected to win. Anything else would be a major disappointment.

On paper, it seems the perfect time to give him a rest and allow other attackers in the squad to take centre stage.

But Ronaldo loves the Champions League. He's obsessed by it. And not playing, especially after his dazzling display against Newcastle, may irk him.

Cavani looks set to be the biggest loser of his new team-mate's return.

And all signs point to him leaving for the South America homecoming he craves at the end of the campaign.

Ronaldo, meanwhile, was delighted after his fine display for United on Saturday.

"I didn't expect to score two goals,” he said.

"I expected one but not two. It was an unbelievable moment.

"It is unbelievable. When I started the game I was so nervous, I swear.

“I did not expect that they would sing my name all game. The reception is incredible but I am here to win games and help the team.

"It was an unbelievable moment. I was super nervous and was thinking last night that I wanted to play good and show I was still capable of helping the team.

“This club is unbelievable and I am so proud. I am going to give everything to make them proud of me.

"Everyone knows the football in England is different than in any part of the world and to be honest it is the most special one."

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