In the clubhouse, with players and media present, Guillen made it clear there was plenty of blame to go around.
Heath Bell gave up a two-out, two-run homer to Aramis Ramirez, which rallied the Brewers to the walk-off win.
Asked on Wednesday who he was sending a message to, Guillen said: "The team, teammates, ownership, fans, the media. It's easy to kick the guy [in the rear end] when you're down. That kid gave up two runs in one inning. People point at him like he's a villain. How about all the guys who pitched from the first inning through the ninth before that kid got in there? That's why I think baseball is unfair."
Guillen noted he wasn't apologizing for Bell's performance. But the team committed three errors, and several other pitchers also gave up runs.
"It felt good," Bell said. "I knew exactly what he was saying. Even though I said I lost the game, it wasn't just me. It really was me, because I threw the pitch. But it really was a team effort.
"I think everything he was talking about is, it's the team. If we lose, if we win, it's the team."
Guillen made it clear he will not tolerate a clubhouse where players criticize each other.
"Look at yourself in the mirror before you look at this kid like a ghost," the manager said. "What happened before that? My point was not protecting him. My point was, this kid gave up two runs at the wrong time, yes. But there are a lot of guys who gave up runs before that.
"If I see some teammates criticize him, they're not going to be on this ballclub any more. I don't care if you're Hanley [Ramirez], or you're [Jose] Reyes. If you're making $100 million, if I hear somebody criticizing their teammate, I'm going to make sure I make your life miserable and get you out of here."