Sounds familiar....
Not sure but in this manga , the Omega used to play football with his twin alpha brother and an alpha friend before his heat ever occurred to him.But later he quits football after he starts getting heats.Then he also gets bitten by that alpha friend and quits football forever moreover even gets married to that alpha.
http://www.mangago.me/read-manga/hebi_no_seikatsu/
If this is not the one then sorry,following
Immoral sandwich
LOL,I thought about it but since the op asked abiut football,I ignored it since it contains baseball ╮(￣▽￣)╭my bad
???
Immoral sandwich seems to be the manga the person is asking for but in immoral sandwich the guy used to play baseball.So I didn't consider suggesting this manga since the op asked about a manga involving football.So my point is, I might have suggested the wrong manga and that's why I said "my bad"
Ah i see
So someone know this yaoi/omegaverse it was about an omega who quit the football when he was in college cause he was raped by Alpha and after graduated he started doing again ??