I think the infected players and staff will get help from the doctor, and I am sure that they will get better again. We hope that there is no problem with sports games, even if there are infected players and staff. As long as the other staff still use the procedures and protocols from the government, I am sure they can minimize the chance to get infected so that the sports event can continue. If the situations getting worst, the sports events need to stop for a while to be checked and make sure that everything is fine.
Sports competitions are voluntary. Athletes usually earn a lot of money and they can afford to refuse to participate in the games if they are afraid of Contracting coronavirus.
I don't know about that, but I think sports competitions will be based on every team. If the athletes refuse to participate in the games, they need to report it to their teams so that the teams can use another player, and the teams can still play on the events, or the teams can cancel of join with the events.
The event organizers need to know about the infected players in the teams. If one team has a player who gets infect, the staff can reschedule the match or the staff will match the other teams.
I don't participate in any of the sports teams so I can't say how things are really going there. However, all athletes are usually quite rich people who can afford not to work for a long time, especially if they have grounds in the form of the fact that during the game they are at risk of contracting coronavirus.