I came across this on another forum. I don't remember this when it happened, but this is crazy in hindsight.
Cecil Cooper played his last game in the majors on July 12, 1987 for the Brewers. He didn't get hurt. The Brewers didn't release him or buy out his contract. They didn't trade him. Cooper didn't retire. Simply, the Brewers benched him for the rest of the season.
Also of note, in 1987, major league teams had a 24-man roster instead of 25 players. So, from July 13 until the end of the season, the Brewers played with 23 guys.
Tom Trebelhorn, the manager, claimed that the GM Harry Dalton told him he was going to trade or release Cooper, but it never happened.
Here's a link to a Milwaukee newspaper article in August of '87:
I can't imagine anything like this ever happening in today's game.