It's not like he's a bad guy, nor was incredibly rude, but you could see the change. First it's important to know that the entire baseball club runs off of donations and volunteers. They never cleaned the grandstands, they never helped with putting away merchandise, they had an Xbox in their locker room when half the team wouldn't even play the game (bullpen and second string players). I got roped in to playing music at the games (walk up songs, in between innings) and never got a thank you, not even from the player living with us. They were constantly told how great they are by the people in charge and how they have a real shot at making it to the majors. Every Friday night the team would get burritos donated by a local restaurant, but the volunteers got nothing. They were constantly having team dinners where our player would come home at 1am after drinking lots of alcohol on game nights (he was over 21 at least). And I think the thing that most bugged me, is at the end of the season "thank you volunteers" lunch banquet, the team got a posh pancake breakfast beforehand, and then when it came time to eat, all of the players got up and were the first ones in line for food. They did not let a single host family or volunteer go before them.
I don't think the players paid for anything besides maybe a few meals when they had away games. They never paid for a hotel nor their uniforms nor their many team dinners. They had free memberships to the local, posh health club. And it was so frustrating as a former college cheerleader who had to pay for everything and fight for everything we got, fight for every ounce of respect, and that was cheering for a school! This is just a summer league for these guys to have fun with, maybe have a scout come out. It's not like they're playing for scholarships or anything. And let's be honest, there is an incredibly slim chance that they would make it to the majors. (None of them played for any school that has an outstanding baseball team, just all average or even bad) MAYBE one player might make it, but he's definitely not going to be the next Derek Jeter or Madison Bumgarner.
You could just see how at the beginning of the season they were fine, but as they kept getting free food, free gym membership, constant praise, and started winning and were treated like kings, they started acting like them.