Sania Mirza may not be able to play for the rest of the season in the WTA circuit. The Indian tennis star has been advised six weeks' rest after suffering a knee injury during the women's doubles third round defeat at the US Open.

The injury has been diagnosed as ruptured left knee meniscus. She has been initially advised a minimum six weeks' rest by a specialist, who examined her in New York.

The Hyderabadi ace has struggled with injuries in the last few seasons. She made a good comeback last year after a career-threatening wrist injury. She zoomed to 64 in the singles ranking after starting the 2011 season at 166.

In the doubles list, she is at her career-best 11.

The latest injury means that Sania's place in the prestigious year-end Championships is also doubtful.

She and her Russian partner Elena Vesnina are frontrunners in the race for the top-four doubles teams.

They are placed third, with 4508 points, followed by Argentine Gisela Dulko and Italian Flavia Pennetta, who have 4106.

There are still eight different WTA events to be played in the 2011 season after the US Open, the last Grand Slam of the year.

Sania's campaign ended at the US Open when she and Vesnina lost 6-7(4), 6-7(5) to the Czech pair of Iveta Benesova and Barbora Zahlavova Strycova.

She also lost in the first round of the singles and mixed doubles, in which she partnered compatriot Mahesh Bhupathi.

Sania is expected in Hyderabad shortly to consult Orthropaedic specialists, who will consider surgical intervention after more intensive tests.

The Indian tennis player had undergone arthroscopy to repair the ACL on her right knee a few years back.