I don't know if you are actually considering this, or just sharing their offer. Congrats on the offer anyway - they obviously appreciate your talents
I guess it would raise you profile (if that's what you want), not only with this sport, but others too, and it would look good on your CV.
Do you know how much traveling would be involved? You could be selective as to what matches you cover unless they want a full season photographed.
I think that maybe the value of your time, not only to shoot the matches, but in PP will make it unrealistic, unless there is money to be had in selling the images.