It means be willing to do with the coach/system is asking of you, not doing what you want to do instead. If you just do what you want, the players and the coaches will know you are not adhering to the game plan, and it likely means you don’t think their game plan works. Well, if we have someone in the team not doing what we practiced and not following our game plan, then for sure we’re not going to succeed. So even if you disagree with the plan, I’m the coach, and if we’re going to have any chance of my plan succeeding, I need you to at least try to follow it - I need you to “buy in”.
It means be willing to do with the coach/system is asking of you, not doing what you want to do instead. If you just do what you want, the players and the coaches will know you are not adhering to the game plan, and it likely means you don’t think their game plan works. Well, if we have someone in the team not doing what we practiced and not following our game plan, then for sure we’re not going to succeed. So even if you disagree with the plan, I’m the coach, and if we’re going to have any chance of my plan succeeding, I need you to at least try to follow it - I need you to “buy in”.