Wayne Rooney's goal record for Manchester United is unlikely to be beaten because it was easier to score in his Premier League heyday, Jose Mourinho claimed on Friday.

Rooney returns to Old Trafford on Sunday for the first time since rejoining Everton in the summer, and Mourinho believes his former captain deserves to be welcomed back as 'a legend'.

The 31-year-old striker broke Sir Bobby Charlton's record in his final season and set a new mark of 253 goals before swapping clubs with Romelu Lukaku who moved to United from Everton for £75million.

Jose Mourinho has asked Manchester United fans to give Wayne Rooney a hero's welcome

This weekend Rooney will return to Old Trafford for the first time since leaving the club

Lukaku has scored six times in his first six games, but Mourinho believes it will be hard for him to emulate Rooney because he joined United later in his career and is playing in a more competitive league.

'I think Wayne spent probably 10 years of his career in a different Premier League than you have now,' said the United manager.

'A Premier League where it was easier to score goals, not just because of the difference between the top teams and others, but also because of the profile and the tactical interpretation of the competition.

'I think this Premier League is much more defensive minded, and much more difficult.'

Mourinho paid tribute to Rooney who won every major honour in club football during a 13-year career at Old Trafford.

He added: 'I think he will get the welcome that he deserves.

The Everton forward should be considered a United legend, according to Mourinho

'Sometimes in this country, the word "legend" comes too easily. That's not the case here. He is a real legend of this club.

'The number of appearances, the number of goals, the number of trophies. I think clearly he is one of the most important players in the history of Manchester United.

'I think the stadium will show him the respect he deserves, I hope, before and after the match, not during the match.'

Asked if United have benefitted from Rooney leaving because his old team-mates have had to fill the gap, Mourinho replied: 'I am not saying that.

Paul Pogba will miss the game against Everton after injuring his hamstring in midweek

'He is an Everton player. I am not going to speak about Wayne more than what I have already told you.

'During the match he is an Everton player who wants to win the match.'

Mourinho also praised Lukaku who will be facing Everton for the first time since leaving Goodison Park in a club record deal.

He said: 'We couldn't be happier. I think that Romelu has a better team than Zlatan (Ibrahimovic) had.

'Romelu's team plays different football and the confidence levels are different. But I think he also deserves credit for that because of the way he plays.'