5 biggest questions for the St. Louis Cardinals in the second half

Which top prospect will make his debut in the second half?

This is where things get fun. We all love talking about a promising future and talented prospects.

Michael McGreevy will be the first name called should a spot in the major league rotation open up in the second half. That much is certain. However, other youngsters could make their debuts this year if there's a need on the team or if these young players force the front office's hand.

According to MLB Pipeline, the Cardinals' top-five prospects are infielder JJ Wetherholt, LHP Quinn Mathews, catcher Leonardo Bernal, catcher Rainiel Rodriguez, and RHP Tink Hence. Behind them are catcher Jimmy Crooks, infielder Yairo Padilla, outfielder Chase Davis, and RHP Tekoah Roby.

Let's remove Rodriguez, Padilla, Davis, and Bernal from these odds. They're all at least two levels away and still relatively young and inexperienced. Hence, and Roby recently went on the IL, and there is still a lot of concern with their health profiles to promote them to the majors. While either could find a late-season bullpen appearance, it isn't likely given their health histories.

That leaves JJ Wetherholt, Quinn Mathews, and Jimmy Crooks as potential second-half promotions. Wetherholt recently got promoted to Triple-A Memphis, and he's on a quick path to the majors. If he can prove that he can handle higher-level pitching with Memphis, we could see Wetherholt make his debut this year. The Cardinals already have a glut of middle infielders, so a trade or injury would necessitate his promotion.

Quinn Mathews is still having some trouble adjusting to the major-league ball at Triple-A. He has a 4.43 ERA through 40.2 innings in Memphis. He's struck out 43 batters but walked 39 already, his total last year in 13 starts at Memphis. His final start before the break featured him going four innings while striking out five and walking only two batters. Finding consistency will be key in Mathews's promotion.

Jimmy Crooks is an interesting candidate here. The Cardinals have ample catching depth at the majors right now with Pedro Pages as the regular and Yohel Pozo as his backup. Ivan Herrera is the third-string catcher, but the team is looking to keep him away from behind the plate to limit injury risks. This makes Crooks a curious candidate.

Crooks isn't hitting as well this year at Memphis as he did last year with Springfield. He has a .260/.321/.440 slash line with 11 home runs in 68 games. He's managed to maintain most of his power from previous years, but he's also striking out at a career-high rate of 27.8%. If the Cardinals want to test Crooks, giving him some late-season at-bats should be a good place to start.

With this being a year focused on player development, the Cardinals will certainly want to see what their top prospects are able to do before the year is out. Trades and injuries will dictate second-half promotions, but expect to see at least one of JJ Wetherholt, Quinn Mathews, and Jimmy Crooks as the calendar flips to September and October.