Alex Corretja has warned Rafael Nadal that he will take time to get back up to speed as he makes his return from injury at the Mubadala World Tennis Championship, which you can watch live or on demand on discovery+.
The 20-time major champion has been out since August with a foot issue but is set to make his competitive return to court in Abu Dhabi this week.
And while Corretja is not necessarily fearful for Nadal's typically strong strokeplay, he believes his Spanish compatriot may need time to readjust to the rhythms of high-level tennis.
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The Eurosport expert has cautioned that Nadal may not move freely immediately on his return.
"What worries me the most about Rafa's recovery are his movements," Corretja said. "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 second that he needs today is what worries me the most. The rest, I think it's a matter of time before he picks up some rhythm.

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Nadal has made a slightly ahead-of-schedule return in a bid to get some sets in his legs ahead of January's Australian Open.
The Spaniard added Marc Lopez, alongside whom he won Olympic men's doubles gold at the 2016 Rio Olympics, to his coaching team last week, and Lopez will accompany him to Abu Dhabi.
Nadal's first match at the World Tennis Championship will be against either Andy Murray or Dominic Thiem, two players who have similarly struggled with injury during the course of 2021.
Corretja thinks the tournament will serve as much-needed preparation for the first major of 2022, which is just more than a month away, though Nadal will also be able to find his form in the first week in Melbourne.
"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 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.
"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 Rafa. 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."
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