Complex sentence: While his best days were already behind him, and he never maximized his potential in singles, he became a successful doubles player who even reached the French Open doubles final in 1989 with Eric Winogradsky.
Split into simpler sentences: While his best days were already behind him and he never maximized his potential in singles. However he became a successful doubles player who even reached the French Open doubles final in 1989 with Eric Winogradsky.