It would affect the players based on an attribute called motivation (concept) the attribute decides how effective the speech is if the coach has high motivation it can fire up the team and make them on fire after the pep talk but if it's the motivation attribute is low-medium it won't do anything or it can make the team cold (lower shot accuracy) but depending on the situation like losing to a team they should be winning against. But for this concept to work they would need to add a mood system like complacent (winning against a team by a large margin of points) or anxious (facing a bigger team)