Republic of Ireland legend John Giles thinks Cristiano Ronaldo would have flourished under Pep Guardiola at Manchester City. 

The Portugal captain was heavily linked with a move to the Premier League champions last week, before ultimately securing a return to Manchester United.

Ronaldo will again wear the iconic number seven shirt at Old Trafford after he signed a two-year contract with Ole Gunnar Solskjaer's side.

"I think he'll add to Manchester United but funnily enough I think he would have added more to City," Giles said on tonight's Off The Ball.

"I think with the way City play and make the chances that they do, they needed an out an out striker that can do exactly what he does.

"I think we would have been perfect for Manchester City but he'll do well for Manchester United but they won't make as many chances as City would have done for him."

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Ronaldo is a clinical genius

Ronaldo will go into his 'second debut' for Manchester United on the back of becoming the outright top scorer in international football history with a brace against Ireland.

His late headers secured a comeback 2-1 win in Faro to keep Portugal at the top of Group A and Giles feels the 36-year-old's ability to produce match-winning moments, even when not playing well, is his best asset.

"His mentality is amazing now. In his early years at Manchester United I thought he was a bit lazy and that he should have been working a bit harder for the team.

"What's amazing really though is his mental attitude. For spells yesterday he hardly got a kick of the ball, he contributed next to. nothing, but then he produces two fabulous headers. And it's far from the first time he's done something like that.

"Now at 36, he saves energy during the match so he's able to able to make the difference like he did last night. He's there to score the goals and he has the temperament and the confidence to be patient.

"He's a fantastic header of the ball. When the ball is in the air, he's as brave as anyone as I've seen in football. Portugal crossed the ball a lot but they didn't just aimlessly hoof it into the box.

"The two goals he scored came from good crosses but most players wouldn't have his ability to score those headers and to be able to come alive when his team needed him.

"He's an absolute genius at being able to find a couple of yards in the box, absolutely brilliant."