Rafael Nadal withdrew from the Paris Masters and the ATP World Tour Finals because of appendicitis surgery and an injured back, but his litany of physical problems doesn't stop there—the Spaniard is also using his extra time off to get his knees examined.

The world No. 3 has chronic problems in both knees, having been sidelined in 2009 with tendinitis in his left knee and in 2013 for his right knee.

Nadal visited a medical clinic in Vitoria, Spain, reports Marca, consulting with one of his regular physicians. The clinic is where he originally had a successful procedure of injections for his left knee.

The Spaniard undergoes surgery next week, and is expected to return for the Abu Dhabi exhibition at the start of next season.