World number one Lleyton Hewitt has urged Spanish Davis Cup team mates Carlos Moya and Albert Costa not to collude in their Tennis Masters Cup clash on Friday. If French Open champion Costa beats Moya in straight sets in the final Red Group match, Hewitt will be out of the tournament he won last year.
Moya qualified for the semis with his win Wednesday over Hewitt.
"It would be bad for the game of tennis if there was anything between them," the Australian said after the match.
"Mathematically I still have a chance of winning the tournament and all I care about at the moment is the number one ranking."
If Hewitt reaches the final in the Chinese sea port he is certain to be crowned year-end world number one for the second successive year. However if he falls before the final and Andre Agassi wins the tournament the 32-year-old will pip him at the 11th hour.
Agassi lost to Jiri Novak earlier on Wednesday, however, greatly denting his confidence and his hopes of becoming the oldest player to finish the year in top spot.
Hewitt's eyes are still locked on the rankings as he prepares for his final group match against Russia's Marat Safin on Thursday. Safin beat him comprehensively in the final of the Paris Masters earlier this month.
The Russian has lost both of his group matches so far but Hewitt said: "My guess is as good as yours what the hell he is going to play like tomorrow so I have got to go out there and be mentally tough.
"The number one ranking comes into your mind going into a match tomorrow. Not too much the tournament, more so for me the number one ranking."