Jacco Eltingh and Paul Haarhuis were the defending champions, but Eltingh retired from the sport on November 22, 1998, and only Haarhuis competed that year.
Jacco Eltingh and Paul Haarhuis were the defending champions but only Haarhuis competed that year with Sjeng Schalken.
Hendrik Jan Davids and Paul Haarhuis were the defending champions, but Haarhuis did not participate this year.
 Davids partnered Ģirts Dzelde, losing in the first round.
Tomás Carbonell and Carlos Costa were the defending champions, but did not participate together this year.
 Carbonell partnered Francisco Roig, losing in the final.
 Costa partnered Christian Miniussi, losing in the first round.
Lucas Arnold and Tomás Carbonell were the defending champions, but did not participate together this year.
 Arnold partnered Martín García, losing in the first round.
 Carbonell partnered Piet Norval, losing in the first round.
Virginia Ruano Pascual and Tomás Carbonell were the defending champions, but had different outcomes.
 Ruano Pascual teamed up with Gastón Etlis and lost in second round to Cara and Wayne Black, while Carbonell did not compete this year due to retiring from professional tennis in 2001.
Jacco Eltingh and Paul Haarhuis were the defending champions, but Eltingh did not compete this year.
 Haarhuis competed with American Jared Palmer as the seventh seed, but they were eliminated in the second round by Javier Sánchez and Jan Siemerink.
Paul Vincent Nicholas Haarhuis (born 19 February 1966) is a Dutch former professional tennis player.
 He is a former World No. 1 doubles player and reached a career-high singles ranking of World No. 18 in November 1995.
 He won six Grand Slam men's doubles titles, five with Jacco Eltingh and one with Yevgeny Kafelnikov.
Tomás Carbonell and Donald Johnson were the defending champions, but did not participate together this year.
 Carbonell partnered Juan Balcells, losing in the first round.
 Johnson partnered Piet Norval and successfully defended his title.
Tomás Carbonell Lladó (born 7 August 1968) is a former professional tennis player from Spain.

Question: Paul Haarhuis and Tomás Carbonell, have which former occupation?
Answer: professional tennis player