Ken Griffey Sr. laughed when asked if the attendees of this year's Breakthrough Series knew how good he was as a player.

“No, they just called me Senior,” Griffey joked. “I used to be Ken Griffey, but they call me Senior now. Period.”

Griffey -- or Senior, as he has been called all week -- is coaching players for the first time as part of the 2021 Breakthrough Series in Vero Beach, Fla. Along with other former players and coaches, he’s focused on teaching player development on and off the field in the five-day camp.

The event, which started in 2008, invited baseball players from the 2022 and ‘23 graduating high school classes to perform at the highest level for collegiate and professional scouts.

“The biggest thing is hustle,” said Griffey on what he’s teaching. “That's what you want them to do all the time. So we've been stressing that. The fact that being out there and running out on the field, like you belong out there. That's what we teach.”

Griffey’s coaching style is majorly influenced not by his distinguished 19 seasons in the Majors, but rather by his time in the Minor Leagues with the Reds -- between his Draft in 1969 and becoming an everyday player in the ‘74 season.

“Now, I will say that from Day 1 when I was with the Reds in the Minor Leagues, if we got caught walking [instead of running], we weren’t going out on the field. So that's the biggest thing. That gives you a positive outlook on what you want to do when you get out.”

Through seminars, mentorship and gameplay, participants in the Breakthrough Series develop and learn from former All-Stars like Griffey Sr. what it takes to be a Major League player. The program is at no cost to the young players and is covered by USA Baseball as a way to expand the sport. One of Griffey’s favorite parts of joining the program is meeting young players from around the United States and creating competition between the best of the best.

“We're having fun, we're enjoying it,” said Griffey. “You know, that's the biggest thing -- just the idea that you become a teammate. You look out for your teammates and they look out for you. Getting to know people from different walks of life ... it's just the nature of the game. You come in, you understand what you got to do. You make friends and you make teammates, and you play a lot more games than anybody.”

Watching and coaching these players has impressed Griffey, to the point where he thinks these prospects could become big league players. The Breakthrough Series has graduated some notable alumni: Dominic Smith (Mets), Ke'Bryan Hayes (Pirates) and Carlos Rodón (White Sox), to name a few.

“That was the biggest thing is that I had played five years in the Minor Leagues,” said Griffey, reflecting on what he hopes the players take away from this week. “You weren't allowed to move up a notch unless you did what you were supposed to do. It's still instinct, period. They have to understand all situations of the game in order to make themselves better. I see some pretty good prospects and that we got some pretty good kids.”