As young players develop very little of the mental side of the game is addressed. Every time a player goes to the next level the challenges are greater for many.
Jackie Bradley was a high Red Sox pick. He was an All American and NCAA champion at Souh Carolina. He blew through the minors. He torched the ball in spring training. He skipped AAA and became an opening day starter for the Sox. He was sent down a month later hitting under .100. The next season he was a stud center fielder but hit .198.
There wasn't room for Bradley on the Sox roster this year. He tore up AAA. Mookie Betts went on the DL. The Sox called up Bradley. They hoped playing well would increase his trade value. He's the hottest hitter in baseball. He's now a lock to be the Red Sox center fielder of the future.
Jackie Bradley could have gone back to AAA and pouted he wasn't in the majors anymore. Instead he reported to spring training early, made adjustments and delivered when he got his opportunity.
Opportunity may only happen once for a player. It doesn't have to be at the MLB level. It could be at the high school or college level. Will your kid be able to deal with adversity and remain mentally ready to perform? Many players in Bradley's situation have washed out of the game.