Knee Injury Forces Seles to Withdraw : Tennis: She pulls out of Oakland tournament, which would have been her third since return.

Monica Seles might have come back to tennis, but her body hasn’t kept pace. Seles, in Oakland preparing for what was to be her opening match tonight in the Bank of the West Classic, withdrew from the tournament Tuesday after aggravating her aching left knee.

The 21-year-old has been plagued by tendinitis since returning to the WTA tour in August after a 2 1/2-year absence while she recovered from a stab wound suffered when she was attacked during a match in Germany in 1993.

Seles returned to the tour carrying a co-ranking of No. 1 with Steffi Graf for her first tournament at Toronto, which she won. She lost to Graf in the final of the U.S. Open in September. The Oakland event was to be Seles’ third tournament, after which she would have received a computer ranking, although she’s guaranteed to retain her co-No. 1 status for six tournaments.

Seles developed the tendinitis while preparing to return to the tour. She said the combination of running to get back into shape and changing court surfaces--she prefers practicing on a clay court--caused inflammation in her knee. She took three weeks off to rest it after the Open.

Seles said she had been practicing on the indoor courts in Oakland for the last few days, but rather than getting her used to the hard indoor surface, the workouts exacerbated the problem.

Seles will not play next week at Philadelphia, which had not been on her schedule. She said she is focusing on being ready for the year-ending championships in New York beginning Nov. 11.