"Clemente can do so much for the Pirates. I don’t think there’s a more colorful player in the league and he’s probably the most popular player in Pittsburgh. He has as much ability as any player in the game, yet, great as he is, he could be greater. He could be our leader, the man we need to show us the way. I’m trying to get him to realize how good he is. You know, Clemente is very emotional and sometimes he’s controlled by the way the team is going. If we’re winning, he’s hitting and doing everything expected of him. But when we hit a slump, Clemente’s spirit gets down, too. If he can get the idea he’s the real leader, he can do the job for us. This [1963] isn't a good year for Clemente. He can be better, much better. With his ability, I feel any time he bats under .350, it isn’t a good season. He shouldn’t settle for anything less than that. When they talk of potential .400 hitters, they never mention Clemente, yet he has all the tools to reach that figure. He hits line drives, he hits to all fields and he has power. And he can run. There’s no question of his arm and his fielding. When you take all of this in consideration, you can see he hasn’t reached his potential."
January 1, 1970
https://en.wikiquote.org/wiki/Roberto_Clemente