Kansas City, Mo. ? Just about every locker in the Royals’ clubhouse has some kind of memento from the first half of the season. Lineup cards from a major league debut, framed in plush velvet and expensive wood. The ball from a first hit, carefully mounted in a custom shadow box.

Evidence of success — and the fact Kansas City remains among the youngest teams in baseball.

So it’s hardly a surprise there have been significant growing pains this season. Just about everybody has taken their lumps, from 22-year-old hotshot third baseman Mike Moustakas’ trouble at the plate to the uneven starts of Danny Duffy, the rookie left-hander many consider a future ace.

The net result is that Kansas City (37-54) once again had the worst record in the American League at the All-Star break, a mark that could have been even worse after the Royals clung to second place as late as May 12.

“I’m very disappointed with where we are record-wise now,” manager Ned Yost said, “but that doesn’t take away my enthusiasm I have with what we’re doing and how we’re developing.”

And that may be the biggest difference from years past: Team officials accustomed to losing once looked to the future with a wary eye; now there is genuine hope that better things are still to come.

That played true during the Royals’ final first-half homestand, when they lost a pair of close games to Detroit before piling up 13 runs in a rout.

The starting lineup for Kansas City that Sunday afternoon had an average age of just over 25 years old, roughly the same as most minor league lineups.

Duffy has become the team’s top starter, with all of 10 big league games under his belt, while the bullpen has been one of the club’s strengths despite being devoid of experience.

All-Star reliever Aaron Crow is just 24, and the elder statesman is 27-year-old former All-Star closer Joakim Soria, who could be dangled as trade bait heading up to the July 31 non-waiver deadline.