MLB: Former MLB Closer Gregg Olson Lays Out Baseball's Unwritten Rules

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Catching Up With Former Orioles Closer Gregg Olson

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Since a pitcher is more in danger of getting seriously hurt by a comeback line drive to the head than a batter is getting hit by a pitch, why aren't they required

Gregg Olson - Wikipedia

Kevin Gausman] It's ridiculous us players have to watch what we say in OUR clubhouse : r/Braves

What are the different types of pitchers in baseball? - Quora

Why Gregg Olson was worth a look for Cardinals

How does being hit in the head with a line drive impact a pitcher's ability to continue playing in a game? - Quora