A catcher in a farm system barren of solid backstop prospects, Grayson Greiner has been a nice surprise this season, hitting his way out of his initial assignment in High-A Lakeland. In 31 games, Greiner hit .312/.385/.752. His only minus was an advertised lack of power and speed. He hit only six doubles, zero triples, and zero home runs in 123 plate appearances. Still, Greiner accumulated a wRC+ of 126 over that span, 26 percent above league average.
After getting his promotion to Double-A Erie, he continued to be brilliant. Through 59 games with the SeaWolves he has been hitting .288/.320/.782 with nine doubles. He has also added three triples and seven home runs, showing power that has never been seen before. The run creation has also remained high; at 111 wRC+, he is an above average bitter at Double-A.
Greiner is looking more like a legitimate prospect this year, which has been a gift to Tigers fans, but his defense has been there all along. It was his defense that got him drafted in the third round back in 2014, with MLB.com's scouting report saying "It's surprising enough to see Greiner as a good defender, given his 6-foot-6 frame. He has a solid throwing arm and receives well, with agility in his lanky frame."
While it is defense that sets Greiner's floor, the development of his bat will be what determines how far he is able to go. As far as the timing of his major league impact goes, he may get a look for backup catcher in spring training next year. However, the Tigers are more likely to look to John Hicks or another catcher outside the organization for 2017. Baseball is baseball, though, and Greiner's name is one to watch.
Single-A West Michigan: Mark Ecker, RHP
Taken in the fifth round, Ecker was the Tigers' third selection of the 2016 draft. A reliever out of Texas A&M, Ecker has a much deeper arsenal than you might expect. Scouts would have liked to see him start, but he was never able to crack a stacked starting rotation as a freshman, so he settled into the Aggies' bullpen. Though being a starter would increase his stock notably, the powers that be in the Tigers minor leagues are apparently trying to fast-track him to Comerica Park as a reliever.
After an 11-game cameo in Connecticut in which he allowed one run and struck out 21 batters over 18 innings, he was promoted to Single-A West Michigan. He has pitched 9.1 clean innings over eight appearances thus far. He has struck out nine batters and allowed eight hits, racking up five saves. While those numbers look spectacular and prone to regression, we have been shown that high-upside pitchers with really good stuff are able to blow away competition in the lower minors (see: Jimenez, Joe). As my personal Most Underrated Tigers Prospect, Ecker's stuff is far better than he gets credit for.
Ecker's fastball is his plus pitch, which tops at 98 miles per hour and was sitting at 95-97 mph when I saw him in his Whitecaps debut. His changeup is also above average, and gets swings and misses with its splitter-esque movement. He also mixes in two bendy pitches in a slurve and a true slider to keep hitters honest. Remarkably, none of his pitches are graded below average, and his control is actually graded above average.
While Ecker is still a reliever, and that caps his value, it is realistic to think he could play as a setup man at the highest level.
High-A Lakeland, Spencer Turnbull, RHP
The organization's second round draft selection in 2014, Spencer Turnbull fits the profile of a stereotypical Tigers' prospect to a tee. He stands at 6'3, weighs 215 pounds, and his fastball is just as big. It sits around 92-94 miles per hour with heavy sinking action and can dial up as high as 98 miles per hour. When I saw him last year at Single-A West Michigan, he was able to pitch into the seventh inning and hit 97 mph twice even that late in the game! He also features an erratic power slider and a below average changeup that still needs quite a bit of polish.
Turnbull spent all of 2015 in a Whitecaps uniform and was their most dominant starter, with both superficial and advanced statistics telling the same rosy story. Over the course of the season, Turnbull started 23 games that resulted in a 11-3 record and a 3.01 ERA. He also was able to strike out 8.18 batters per nine innings, but also racked up 4.01 walks per nine. Despite that high walk rate and a high BABIP, Turnbull was able to manage a 3.01 FIP.
This year, a mystery injury kept the Tigers' favorite redhead out of the action for quite a while. After six rehab starts in the Gulf Coast League, he was assigned to the Advanced-A Lakeland Flying Tigers, where he has performed very well. In an admittedly small sample, he has thrived on a healthy diet of High-A hitters, with a 23.2 strikeout rate. He has kept the walks in check so far, allowing only 7.4 percent of batters a free pass to first base. This new and improved version of Turnbull has put together a tidy 2.41 FIP, but is also benefitting greatly by hitters being very unlucky against him, hitting a minuscule BABIP of .262.
Long term, Turnbull has a ceiling of a No. 4 starter, but that depends on on how well he is able to refine his command and his changeup. If he cannot do those things, he can be a power righthander out of the bullpen with a devastating sinker-slider combo. He has been extended an invitation to the Arizona Fall League, so that will allow him to gain back some lost developmental time. Once he is able to get a little more control over his pitches and a little more polish himself, there is very little that can stand in his way.