Why is it that, when sport is treated in fiction, it is rarely head-on: it's not the main theme but the background; it provides 'narrative flavouring'. Mark Lawson suggests as the main reason for this that 'the most durable and popular stories aspire to universality' and there is no really universal sport. Sports are tied to national, regional and other cultural specificities.
As important as this reason may be, I think there is another as crucial and possibly more so. It is that the hold which sport has on so many people is linked to uncertainty of outcome and to the passions, the tensions, and indeed the subtleties and beauties of any game, that this yields. I'm not saying that there aren't beauties or attractions just as great, or even greater, in life; but there aren't any that are quite the same as that provided by uncertainty in sport. And for some reason the uncertainty can't be replicated in fiction or simulated to a sufficient degree. I'm not sure why that should be, since fiction manages to do most other 'simulations' well enough to involve people. But the thrill of the sporting contest - well, to the best of my knowledge anyway, it can't do that successfully.
You have to care what happens in the here and now. Hard as it is to understand why people do care about the outcome of mere games, it is harder to recreate that caring in a reader. There are many, of course, who don't care even about the real thing. But for those of us who do, attempts to fictionalize the experience produce only a pale imitation.