For better or worse Don Copper was a staple of the White Sox organization for over three decades. For eighteen seasons he owned the title of White Sox pitching coach. He was stripped of that title in October when he was fired along with manager Rick Renteria.  After being tight with Jerry Reinsdorf for so many years it came as somewhat of a shock to Cooper and he is salty about it.

Cooper Is Not Happy With The White Sox

This is the first Spring Training that Don Cooper has spent unemployed in quite some time. He isn't taking it very well. On Thursday in an interview with 670 The Score’s ‘‘Parkins & Spiegel’’ show he did not hold back his feelings.

“I spent more than half my life there,” he said, “and it’s not fun when people you really look up to and admire and care for-  care for, that’s the best way to put it don’t care for you quite as much. It's Not fun. That's my whole thing with the White Sox. That's My Statement.”

When asked a follow up question on who didn't care for him? He responded simply by saying "obviously nobody". Cooper has a right to be angry with the White Sox, but it was time to move on. For years Cooper was regarded the best pitching coach in baseball. He oversaw the 2005 pitching staff which was instrumental in capturing the World Series title that season. His pitching staff set a record that will never be broken. In the 2005 ALCS the White Sox threw four consecutive complete games. However in recent years the reluctance to embrace analytics caught up with him. He failed to develop Reynaldo Lopez and Carlos Rodon into the pitchers the White Sox had hoped. Dylan Cease failed to take the next step under his tutalige and Lucas Giolito turned to his former high school pitching coach to fix his mechanics. That pitching coach, Ethan Katz, eventually replaced Don Cooper.

Ethan Katz Takes Inadvertent Shot At Cooper

Players have been raving about Ethan Katz in the short time they have worked with him. He is very detailed orientated. He has been tasked with overseeing this young blossoming pitching staff. One of his top priorities is to fix Reynaldo Lopez's mechanics. The White Sox recently released a great video of Katz working with Lopez.

In the audio you can hear an interesting conversation between López, Katz and Jonathan Lucroy. Katz Besides the mechanical alteration, you’ll also want to listen to the audio. In particular, just before the two-minute mark is a conversation between López, Katz and Jonathan Lucroy, who is catching the session. If you listen closely you can hear Katz take a inadvertent swipe at Don Cooper.

Lucroy [to López]: … "curveball? What do you like throwing better with two strikes?" Katz [to Lucroy]: "So, the curveball. He threw it with the Nationals. That was his best secondary pitch. He came here, he dropped it. So the curveball is coming back into the picture this year. It’s a brand new– it’s not brand new, but it’s new, it’s been a while. So it’s back in the picture and getting him to re-acclimate that is kinda new for him."

Jim Margalus of Sox Machine does a great job breaking this down. Cooper favors the slider over the curveball. He believes it is a easier pitch to get strikes with. While that has worked in the past with pitchers like Gavin Floyd, the recent returns have not been very good. López throws a good fastball and a curveball has proved to be an effective weapon when paired with a high fastball. So sticking with the curveball for López makes sense. If you look at López's curveball usage from FanGraphs show how his curveball usage shrunk over the years with Cooper at the helm.

• 2016: 25.3% (with Washington)
• 2017: 12.9% (with Chicago)
• 2018: 5.6%
• 2019: 6.6%
• 2020: n/a

Time will tell if Katz can transform López into the pitcher the White Sox hope he can be. But based off of his new arm mechanics the arrow is pointing in the right direction.