There are a number of reasons why the first drink breaks in a Premier League match.
The first drink break occurs at half time, 10 minutes into the second half. The reason for this is that during the break it’s possible for players to go and get an injury looked at or substituted with another player if needs be. There might also be injuries sustained during the first-half which need to be checked over by an expert physician who is on standby behind the scenes. The third and final break comes towards full-time, when each team takes off every subsequent substitute they made during the game and return back onto their original squads of 11 players (unless they’ve lost more than five substitutions).