Manchester United are adamant Cristiano Ronaldo is not for sale despite the frustrated star reportedly asking the club to leave if an acceptable offer arrives.

The 37-year-old made a shock return to Old Trafford last summer, joining from Juventus for a deal rising to 23 million euros (£19.6m).

Ronaldo scored 24 goals in all competitions and was named Sir Matt Busby Player of the Year, but individual quality was unable to prevent his first season back at United ending trophyless and sixth in the Premier League.

That finish means Europa League football awaits rather than the Champions League – a prospect the veteran is not enthused by having played at Europe’s top table throughout his career.

Cristiano RonaldoCristiano Ronaldo scored 24 goals for Manchester United last season (John Walton/PA)

Ronaldo has reportedly asked to be allowed to leave if a satisfactory offer arrives, but a senior United source indicated to the PA news agency that the forward is not for sale.

The stance was the same last weekend when it emerged that agent Jorge Mendes had discussed his client in a meeting with new Chelsea owner Todd Boehly.

Ronaldo has one year remaining on the deal he signed last summer and new United boss Erik ten Hag has expressed his excitement at working with the record-breaking Portugal international.

United’s international players are due to report for training in the coming days ahead of flying to Thailand on Friday for the start of their pre-season tour.