"What worries me most about Rafael Nadal's recovery are his movements" - Alex Corretja

Rafael Nadal has been away from competitive tennis since July after a chronic foot injury resurfaced at Roland Garros. The Spaniard was forced to sit out most of the season and missed the US Open, Wimbledon, and the Tokyo Olympics along the way.

After a minor operation, Nadal returned to the practice courts in October and is plotting his comeback to the ATP tour in 2022. The 35-year-old is set to feature at the Mubadala World Tennis Championship exhibition in Abu Dhabi this week ahead of the Australian Open.

Although the Spaniard looks to be on track with his recovery, former World No. 2 Alex Corretja has expressed his concern about Rafael Nadal's return to the tour.

Corretja said that while Nadal does not require much time to get into rhythm, it is the extra "half a second" he will be missing in his movement that may cost him dearly after his return.

"What worries me the most about his (Rafael Nadal) recovery are his movements," Corretja told Eurosport. "His mobility on the court, his intensity, the way he is going to move, the way he will do the supports when he hits the ball. When he moves well and is well supported to hit his backhand and arrives perfectly to play with his parallel forehand and dominate, Rafa is almost impossible to beat. The problem is how he gets to that ball so he can be well supported and hit well."

"That extra half a second that he needs today is what worries me most," Corretja added. "The rest, I think it is a matter of time before he picks up rhythm."

Rafael Nadal will be looking to take the lead in the all-time Slam race against Novak Djokovic and Roger Federer at the Australian Open. The trio are currently tied on 20 Majors each. Corretja said the first week in Melbourne will be crucial for the Spaniard to get into form and rhythm.

"He is going to get to the Australian Open and, when you have not competed for so long, these players are so good that they win many matches, but your body is not used to it and you get other pains in the shoulder or back," he said. "He has to pick up the rhythm during the tournament."

"Rafa is already good enough for the first week of the Grand Slam to serve as a preparation. Before, maybe he didn't think so, but his level of tennis and his physique require that during the first week of a Grand Slam, he must find a good rhythm," Corretja added.

Playing Andy Murray is a very good test to see where Rafael Nadal is: Alex Corretja

Andy Murray (L) and Rafael Nadal

Rafael Nadal joins the likes of Andy Murray, Andrey Rublev and Dominic Thiem at the exhibition event in Abu Dhabi. Corretja believes that while others will be formidable opponents, Andy Murray will pose a stern test for Nadal, given the Scot's intelligent game. The Spaniard will face either Murray or Thiem in the semifinals.

"I think it would be nice to see him [play Andy Murray first in Abu Dhabi], because he is a very smart player who knows perfectly how to play against Rafael Nadal" Corretja said. "I think playing with Andy can give him a necessary rhythm to play two-and-a-half hours in a very tough match, but at a pace that he likes."

"With Thiem it might be too explosive. Andy is different, he plays fast, he plays defensively, on offence ... it's a very good test to see where Rafa is," he added.