JOHN McENROE described Andy Murray’s return to competitive tennis as “very promising” but said the Scot could claim the men’s doubles title at Wimbledon and it still wouldn’t offer many clues about how he might fare when he returns to singles action.

The former world No.1 and three-time Grand Slam winner in singles followed up his weekend heroics with Feliciano Lopez at Queen’s Club with a 6-2, 6-4 first-round defeat with Marcelo Melo against the world’s top pairing Robert Farah and Juan Sebastian Cabral at Eastbourne.

Admitting he had a stiff back after his sudden return to action, the 32-year-old is scheduled to make an emotional return to SW19 next week in the doubles alongside France’s Pierre-Hugues Herbert, with a return to singles pencilled in for the autumn.

HeraldScotland:

READ MORE: Judy Murray feared Andy Murray's career was over just 5 months ago

McEnroe, speaking on behalf of espn.co.uk, said Murray was already a contender to take a title – or two as he ponders his mixed doubles partner – at Wimbledon this year, but his prospects for a full return to singles action remained impossible to second guess.

“I think he has a chance to win it [the doubles at Wimbledon] but he could also lose first round,” McEnroe said. “That is the bottom line. It would be great if he won it, although even with that, I don’t think you will be able to determine how he will be in singles, how high his ranking will go.

“I’m glad he is doing it, feeling it out right now, and we will see what happens. But there is no question with the way he plays, and returns, if he is into it competitive-wise, that he could go all the way – but even after that it is totally unpredictable.

“While Andy has talked about being pain free, doubles is obviously a different animal to singles, best of five is different to best of three with a third set tie-breaker. But it was nice to see him eager and into it and looking relatively healthy.

“You can’t really determine how the body reacts if you start playing singles matches, or if you are on hard courts instead of grass. But it looked very promising and that is great. And I think everyone wants him to come back and then be able to leave on his own terms.

“He’s covering half the court and not moving the same way but I think everyone was very happy to see he has made some real progress. But I’m sure there was a let-down physically and mentally [after the Queen’s win].”

HeraldScotland:

READ MORE: Tim Henman: Andy Murray isn't returning to go on a sightseeing tour

In the Scot’s absence from the men’s singles at SW19, the main suspects are the three other men who have shared out the last 16 titles – Roger Federer, Novak Djokovic and Rafa Nadal.

The Mallorcan expressed disappointment yesterday about the fact Wimbledon’s unique seeding formula will likely bump the world No.2 down to be the third seed in Friday’s draw, which would mean he may have to play both Federer and Djokovic to claim the title, but McEnroe, who still sees the winner coming from those three, doesn’t feel he has too much cause for complaint.

“It would be hard for him to complain too much about Federer going in ahead of him – considering Federer’s record at Wimbledon,” McEnroe said. “Maybe if he was two he would only have to play one of them so I get it.

“It would be highly surprising if it was not one of those three guys, but I think a lot of us want to be surprised.

“I think if you are looking at other potential winners you have to look at guys who have been injured, like [Kevin] Anderson or [John] Isner, do they have the fitness? [Milos] Raonic, guys who can do damage. [Stefanos] Tsitsipas would almost be the most likely to do it and I still think this young Canadian, Felix-Auger Aliassime, while he is still learning on grass, is showing a lot of unbelievable signs. He’s 18 and looks like he is 25, Outwith the top three, I think he has as good a chance as anyone.”