I have to confess I haven't read the article. My first thought though was this would work only if the participants in Maths lessons are as keen as football players. Football(rugby in my case) is fun, even now as a middle-aged man I have vivid memories of playing rugby but hardly any memories cracking hard maths problems. I was motivated to play sport, it was fun. Maths was fun but not to the same level as a sport.