Interesting. All of the research I've seen on creatine indicates that it increases anaerobic performance (weightlifting and sprinting). This is because creatine is used via the phosphagen system to provide energy for 10 seconds.

Since football (soccer) matches last 90 minutes and require nearly constant motion, I'd characterize them as an aerobic activity. And endurance is something that creatine doesn't help. So these soccer players probably are taking creatine and it would certainly help them train their speed and strength in practice, but I highly doubt it helps them run hard the whole match.