3. Carlos Rodon
The Chicago White Sox never allowed Carlos Rodon to become their ace.
The Chicago White Sox had a promising young prospect in Carlos Rodon a few years ago. He was good for them early on.
However, injuries and inconsistencies didn't allow him to complete his development in the traditional way. Of course, this seems to be the White Sox way.
Rodon had an elite year in 2021 as he was one of the best pitchers in the American League. Then, right when he was finally reaching his potential, the White Sox couldn't even extend him a qualifying offer.
He went on to play for other teams but the White Sox could absolutely say they failed to develop him into an ace.
It is a shame because Rodon would have been a great ace to have on the staff for a long time with this team along with the other failed aces.