John McEnroe said it was possible Andy Murray could get back together with former coach Ivan Lendl after the reigning champion was dumped out of Wimbledon.
Murray's straight sets loss to Bulgaria's Grigor Dimitrov on Wednesday meant he had failed to reach a single final since beating Novak Djokovic to become the first British man to win Wimbledon for 77 years.
Under the guidance of Lendl, one of McEnroe's fiercest rivals in the 1980s, Murray became a two-time Grand Slam champion, winning the 2012 US Open as well as Wimbledon.
But with Lendl having taken Murray from contender to winner, the pair parted company in March.
Shortly before Wimbledon, Murray stunned many within the tennis world by hiring France's Amelie Mauresmo as he became the only leading male player with a female coach.
Mauresmo won Wimbledon herself in 2006 and last year oversaw compatriot Marion Bartoli's shock ladies singles win on Centre Court.
Three-times Wimbledon champion McEnroe, now a respected commentator, said it was too soon to make a judgement on how well Mauresmo had coached Murray but added it would not surprise him to see Lendl, who quit because he could not devote as much time to the job as the player wanted, brought back into the 27-year-old's camp.
- 'Give Amelie a chance' -
"I'm amazed he ever got rid of Lendl in the first place," McEnroe said while working for BBC television.
Murray himself has made no suggestion he could be calling on Lendl again but McEnroe added: "I wouldn't put it past the two of them.
"Having said that, I would give Amelie more of a chance. You can't expect her to do anything now. But lurking in the background..."
"I think Mauresmo's done an excellent job coaching other people. There's no reason to suggest she can't do a good job coaching Murray," the 55-year-old American insisted.
But following a dominant 6-1, 7-6 (7/4), 6-2 quarter-final win for Dimitrov, four years younger than Murray, Mauresmo's position was being called into question by the British press.
The Times, under the headline "Murray begins search for answers", said he would "take the next few days to consider if Amelie Mauresmo remains the person who can help to turn him back into a grand-slam champion."
The Scotsman also said it had been agreed to review Mauresmo's position as coach, describing the Frenchwoman as a "surprise choice".
Meanwhile the tabloid Sun captured the mood of many British sports fans by running a photograph of Prince William's wife Kate, gasping in despair as she watched Murray's defeat from her place in the royal box on Centre Court.
Last year Murray became the first Briton since Fred Perry won the last of his three successive titles in 1936 to win the Wimbledon men's singles and home hopes were high for a repeat.
However, after Wednesday's loss, the Sun's back page was dominated by a close-up of Murray with his hands to his face and the headline "Will I ever win it again?"