Andy Murray can be competitive immediately at next month's Australian Open if he has fully recovered from back surgery, says John McEnroe.
The Briton had surgery in September and has not played competitively since.
"If he's healthy, he is going to be one of the guys who can go the distance [in Australia]," said seven-time Grand Slam champion McEnroe.
But Tim Henman said Murray must "remain patient" and not rush his comeback if he wants to be a force in 2014.
The first Grand Slam of 2014 starts in Australia on 13 January.
Murray's lingering back problem forced him to miss the French Open in May, but he recovered to become the first Briton to win the Wimbledon men's singles title since Fred Perry in 1936.
In September, his defence of his US Open title ended in the quarter-finals, but he went on to enjoy success with his GB Davis Cup team-mates, who secured their place in the 2014 World Group.
Murray, 26, then underwent surgery and missed the recent ATP World Tour Finals in London as he recovered.
McEnroe believes the break from the sport could have helped Murray, just like it did Rafael Nadal, who took seven months out before returning in February to win 10 titles, including two Grand Slams.
"It's going to be unpredictable when you haven't hasn't played," added McEnroe, who is playing in the Masters at the Royal Albert Hall this week. "But you could make the argument that it could help him.
"I think mentally, he was a little whipped at the [US] Open, he needed to regroup - it had been an incredible but crazy 12 months for him.
"Now he's had a chance to hopefully get things right with his back. And if that's not right, it's going to be tough.
"Maybe he's going to have to think longer term, but hopefully he'll come out firing the way Nadal did."
Former British number one Henman believes Murray, who returned to practice after his operation late last month, must make a full recovery after surgery his priority.
"I think it's most important for him to remain patient," he said. "To have any sort of surgery is invasive and there are always a few unknowns.
"He's got to make sure that when he does come back, he's 100% fit and healthy and ready to compete to try and win the biggest and best tournaments because that's what his level is and that's what his career is about.
"From what I hear in Miami, with the training he's been doing, things have been progressing well.
"He's still got another three or four weeks of practice. Fingers crossed he'll be ready to compete in Australia."
But Henman believes it may not be so bad if he missed the Australian Open, as Nadal did this year before going on his impressive run which saw him end the season as world number one.
"It's important to reflect on what Nadal did," said Henman. "He had seven months out, which is a lot longer than Andy, and he didn't have surgery.
"He decided he wasn't ready for Australia, he didn't play. He took that bit of extra time and you could see the benefits of that at the end of this year."
Tim Henman was speaking at a coaching clinic for tennis charity Give It Your Max in conjunction with Statoil's Heroes of Tomorrow initiative.