Rafael Nadal is wary about his return to tennis after a seven-month layoff and believes it may be some time before his injured knee is fully healed.

Nadal told Canal Plus television Friday he's "prepared to accept" that his knee "may not respond well at the beginning."

The 26-year-old Spaniard is set to play in Abu Dhabi on Dec. 27. He has considered playing off and on during the first three months of 2013. Nadal says his goal is to be back in top form for Monte Carlo in April.

The match in Abu Dhabi will be his first since he was sidelined with tendinitis in his left knee after a second-round loss to 100th-ranked Lukas Rosol at Wimbledon in June.