A spokesman for Dutch soccer federation president Michael van Praag, one of Blatter's opponents in the May 29 election, says "it is too early to talk about which candidate might have the best chance."
The spokesman, Sebastiaan van der Laan, says "our shared, collective goal is to achieve change within FIFA."
Former Portugal great Luis Figo and FIFA vice president Prince Ali bin al-Hussein also are running against Blatter.
Sepp Blatter loses appeal at CAS against 6-year FIFA ban