LONDON, June 20: World number-one Pete Sampras, who begins his bid for a fourth Wimbledon singles crown next week, has admitted that he owes a lot to Andre Agassi.Agassi, however, pulled out of the championships today.``I played Andre quite a bit a couple of years ago and he defintely made me a better player,'' said Sampras.``One thing tennis needs right now is a rivalry. We don't have one that can really sell the game. Andre and I had it for a little bit a couple of years ago and that really helped out the game. Where I am in my career now I need that sort of challenge again to get me going,'' he added.
