Well Angel would never get an assignment! lol.....I would like to think MLB managers would not have a say so in who umps their games. I cant imagine Joe Maddon calling up the head of the umpires union and asking him to assign or not assign certain umps to Angel's games.
If you are a college ump and being liked or preferred by college coaches could affect your schedule/income, therein lies a problem and may be contributing to the non-calls on illegal pitches. Does the if you want to work a lot better not enforce the rules mentality exist?
The MLB Umpire's Union is STRONG. No way they would allow managers to dictate assignments. No way.