London, Mar 9 (IANS): Portugal's Cristiano Ronaldo has reportedly held talks with his agent Jorge Mendes over leaving Manchester United.

There have been rumours since Manchester United dropped the 37-year-old for the derby clash with Manchester City on Sunday with interim boss Ralf Rangnick claiming his absence was due to a hip injury, but there were reports that Ronaldo was not injured.

Ronaldo is believed to have been left 'furious' after being told that he would not be in the squad for the clash at the Etihad Stadium, which resulted in him taking a trip to his native Portugal for warm weather training.

Ronaldo is said to have been discussing his future with Mendes, who has tried to "calm the player" down after a row with interim manager Ralf Rangnick, reports mirror.co.uk .

Rumours suggest Rangnick told the veteran, who turned 37 last month, he would be deployed as a "super-sub" at the Etihad for tactical reasons.

That reportedly encouraged Ronaldo to complain about his ongoing hip injury, which caused him to miss two games - both against Aston Villa - in January.

It's thought there is an "uneasy tension" around United's Carrington training ground due to Ronaldo's mood.

Ronaldo's own form hasn't been great, scoring just once in the Premier League since the turn of the calendar year - his worst run of form for over a decade.

He's scored 15 goals in 30 games for United this term and will need to have a sensational end to the season if he's to get anywhere near his tally of 36 for Juventus last term.

Ronaldo missed United's 4-1 defeat to rivals Manchester City at the weekend and didn't train on Wednesday morning due to a hip flexor problem.