Manchester United are uncertain whether Cristiano Ronaldo will play against Aston Villa at Optus Stadium later this month.

Ronaldo, who wants to leave Old Trafford, has not reported for pre-season training, citing family reasons, which the club has accepted according to reports from England.

The Portugal star and his girlfriend Georgina Rodriguez lost their newborn son in April.

United do not know if Ronaldo will be on their private charter flight this Friday.

Ronaldo, pictured, has been keeping fit at Portugal’s Cidade do Futebol training base.

The soccer giants are due to fly to Thailand, where they open their tour against Liverpool, before taking on Melbourne Victory and Crystal Palace at the MCG and Villa in Perth on July 23 in front of a sell-out Optus crowd.

Leeds United play Crystal Palace the previous night.

Ronaldo’s agent, Jorge Mendes, has reportedly spent the past few weeks selling the ‘Cristiano effect’ to clubs

United have insisted Ronaldo is not for sale but Chelsea co-owner Todd Boehly has reportedly been in discussions with Mendes along with Bayern Munich, Barcelona and Napoli.

It is understood that when the WA Government was trying to bring Juventus to Perth three years ago they had Ronaldo’s appearance written into the contract.

If he did not play, the payment to the club, around $5 million would be reduced.

The Government said: “All travelling clubs have committed to bringing their full first team to ensure top players participate in the matches.”

The clause in their contract means Manchester United do not have to name Ronaldo. If he cites “family reasons”, is injured or otherwise unavailable he would not fly.