Nadal nervous about return from knee injury

Madrid: Rafael Nadal says he is nervous about his return to tennis after a seven-month injury layoff, and believes it may be some time before his injured knee is completely healed.

Nadal said on Friday that "I'm prepared to accept that my knee may not respond well at the beginning" and has considered playing off and on during the first three months of 2013.

The 26-year-old Spaniard is set to play in Abu Dhabi, United Arab Emirates, on December 27, his first action since being sidelined with tendinitis in his left knee following a second-round loss to 100th-ranked Lukas Rosol at Wimbledon in June.

Nadal says his goal is be back in top form for Monte Carlo in April.