In small sports leagues, including eSports, there are often cases where fixed matches are made, in which not a team participates, but one player who will pretend that he is very fit today and thus will drag the whole team to defeat. Such cases are known in small tournaments in Dota 2, and I think you know all the cases in small football leagues.
There are films about the investigation of such cases, which even show the correspondence of the compromised player with the customers.
Yeah, it's really possible especially those local games that bookies also offered there are chances that fix matches can be executed and either the team owners or the players or also the refs are involved, there are sequences that those types of games are controlled by numbers of facilatators who really taking advantages of those local gamblers who loves supporting this kind of games.
The involvement of the players or the managements will surely affects the outcome of the game, as they are part of the manipulation and execution of the plan.