When a prospect will be promoted is always a hot topic of conversation, even when it's just from one minor league level to the next. That only gets amplified towards the end of the year, as organizations weigh the possibility of giving their prospects, especially top prospects, a taste of the next level in preparation for the year to follow. There is no right or wrong method of making this decision, rather an individual assessment of each situation to do what is best for both the prospect and the organization.
With his dominance of the Florida State League this season, it has seemed likely for a while that Pirates top pitching prospect Tyler Glasnow would be promoted to Double-A at some point this season. Glasnow has dominated the FSL to the tune of a 1.52 ERA over 20 starts and 11.2 strike outs per nine innings. Amazingly that's actually down from his astronomical strike out totals from 2013, but serve to further establish his track record for missing bats.
But as Tim Williams of Pirates Prospects points out, by having not promoted him at this point, the Pirates actually now have an opportunity for Glasnow to build more innings as the Bradenton Marauders make a run into the FSL playoffs:
About a month ago it might have made sense to get him up to Altoona for a few starts at the end of the year. Now? Bradenton has been playing well, has a good shot of making the playoffs, and that would give Glasnow the opportunity to play in meaningful games, all while possibly getting some extra work this year in the post-season. Glasnow is not going to be in the majors next year. No matter when he would have been called up to Altoona this year — whether that’s yesterday, today, a few weeks ago, a week from now — he’s going to spend the majority of next season in Double-A.
Williams' point is well taken and correct. At this point, promoting him won't speed up his timetable to the majors (as a mid-season promotion might have), so what's the point of rushing him? Pitching in a post-season atmosphere could be a valuable experience for Glasnow.
Additionally, despite Glasnow's success this season, he still has many developmental steps remaining to take. His walk rate is still far too high for a starting pitcher, and he's been able to get away with it because FSL hitters haven't been able to square him up consistently. His secondary pitches still need work, as this scouting report by Chris King of Baseball Prospectus shows. Glasnow has the potential for two plus pitches, but his curveball remains inconsistent and his change-up is currently below-avearge.
Glasnow himself is even quoted in this article by Ashley Marshall of MiLB.com after last night's impressive performance that there are nights he can't control his off-speed pitches and has to lean heavily on his fastball.
"It was pretty apparent it was one of those days when I would struggle with my curveball and changeup," Glasnow said. "I tried to make adjustments and find my curveball, but it just wasn't falling for me. So I had to be extra good with my fastball and not leave it over the plate. It was a one-pitch night for me and I thought I did a pretty good job with it.
More advanced Double-A hitters who have a better recognition of this will be more able to exploit that weakness. Few, if any, pitchers can make it to the majors simply on the reliance of their fastball, and by promoting him too soon, the Pirates risk getting him to within striking distance of the majors without having fully developed everything he'll need for success there.
Which, of course, is part of the developmental process and is not reason alone to keep him out of Double-A for long, but at this point, it is reason enough to let him finish the season with Bradenton. The difference between him getting to Altoona now and next April is minuscule, but with the potential for four or five more starts this season (assuming a playoff appearance), there is still a chance for Glasnow to take a few important developmental steps season.