Cristiano Ronaldo's shock return to Manchester United was the Premier League's headline signing in this summer's transfer window.

Ronaldo is back at Old Trafford after leaving for Real Madrid 12 years ago and United boss Ole Gunnar Solskjaer said he envisages playing the 36-year-old as a centre-forward.

Here, the PA news agency looks at which players' places are under threat due to the Portugal star's arrival.

Edinson Cavani

Cavani spearheaded United's attack for most of last season, scoring 17 goals in 39 appearances in all competitions. Solskjaer also said after Ronaldo's return that there would be times when he plays with two and sometimes three players up front and the 34-year-old Uruguayan could form a potent partnership with Ronaldo. But as United's main out-and-out central striker until now, he will be among the first to seek assurances.

Anthony Martial

Martial has played as a number nine in a front two and as part of a three-pronged forward line during his time at Old Trafford and has proved his versatility. In his only start so far this season, the Frenchman was the central striker, but that role will no longer be up for grabs so long as Ronaldo stays fit and with Marcus Rashford, Jadon Sancho and Mason Greenwood all vying for roles on the flanks, Martial could be the one who is squeezed out.

Jesse Lingard

Lingard rediscovered his form while on loan at West Ham during the second half of last season and has been rewarded with an England recall for the upcoming World Cup qualifiers. He prefers a central attacking role behind the main striker and can play on either wing, but with both Ronaldo and Sancho added to Solskjaer's forward options, the 28-year-old must stay at the top of his game if he is to hold down a regular starting place.