Calcutta, Nov. 6 :    Calcutta, Nov. 6:  Just when Leander Paes was beginning to prosper again, another injury has sidelined him. Forced out of tennis for three months in June by a wrist problem, it's the knees which are bothering him now. Paes, who did well in singles at the Charleroi Challenger last week - losing 6-7, 5-7 to Jan Siemerink in the semis - had to fly back to his Orlando base this evening. He was due to play with Mahesh Bhupathi at the Lyon Grand Prix this week. 'I have an inflammation of the tendinitis on both knees,' Paes said when The Telegraph caught him on his mobile at New York airport where he was waiting to catch a connectng flight to Orlando. 'I don't think I'll be able to play in Paris (Masters series event) next week also.' Paes, who played four singles and two doubles matches at the $ 100,000 Charleroi Challenger last week, felt that the hard indoor surface could have caused the problem. 'I played some long matches and did a lot of running. Maybe, that did the damage,' he said before adding ruefully: 'Fifteen years of toil is taking its toll.' Does he fear the worst - pulling out of next month's World Doubles in Bangalore? 'That's a long way away. Hopefully I should be okay by then. Let's see what my doctor says in Orlando.' For all those who prayed for Paes-Bhupathi's reunion earlier this year, fingers will once again have to remain crossed.