There are bittersweet emotions because he's no longer Chris Sale's pitching coach, but Don Cooper is excited about the future of the White Sox.

The team's veteran pitching coach joined the White Sox Talk podcast on Tuesday and said even though he's sad see Sale go, it's hard to overlook the talent the team has received in return. Last month the White Sox traded their five-time All-Star to the Boston Red Sox in exchange for four prospects, including Michael Kopech. The club also added Lucas Giolito and two other pitching prospects in a trade for Adam Eaton.

"When I saw Kopech, my eyes lit up," Cooper said. "Not only is he a big strong son of a gun, the stuff out of his hand is really good, life, energy stuff. He's just untapped talent right now. He's 20 years old. But he's already moved up the scale.

"Delivery-wise it was like, 'Whoa.' Everything I like, he does. ...

"If he stays healthy he has a chance to be a killer."

Cooper also has high hopes for Giolito, baseball's top pitching prospect in 2016, who posted a 6.75 ERA in six big league games last season. He discounted Giolito's struggles as a small sample size and hopes to maximize the pitcher's talent.

"He still has his good stuff," Cooper said. "We've got to mix it up. We need more strikes. We need more consistency."

[SHOP: Gear up, White Sox fans!]

Cooper also noted that the stuff of Reynaldo Lopez, acquired with Giolito and Dane Dunning from Washington for Eaton, caught his eye. Combined with the pitching prospects already in the organization, Cooper thinks the White Sox have a talented farm system.

"Looking around, all of a sudden, combined with the younger pitchers we had in the system already, the injection of these guys that Rick (Hahn) has traded for, it's giving us a stronger, stronger system," Cooper said. "We’re amassing a lot of good talent."

Cooper said Sale is the most talented pitcher he's ever coached and he'll miss their everyday relationship. He described Sale as one of the 10 best pitchers on the planet. But Cooper hasn't been surprised by any moves since the White Sox allowed Mark Buehrle to leave via free agency.

"It's sad that Chris is gone because my individual everyday relationship with him is over as a coach," Cooper said. "But the exciting thing is one of the reasons, the excitement of the guys you get back in return.

"It was mixed. 'Listen man, I'm sad you’re leaving because of that, the relationship. The everyday relationship is no longer there. We're friends.' I know this guy. I've seen every pitch in the big leagues he's thrown.

"When you get to see every pitch and you're with them every single day and that relationship is over, it's sad in some ways. But this has happened before. It happened to Buehrle. If it can happen to Buehrle, it can happen to everybody."