Tigers fans knew the club’s contention window was likely over at the end of the 2016 season, but letting go is never easy. Ownership tried to keep the hope alive in the 2015-16 offseason by signing Justin Upton and Jordan Zimmermann to nine-figure contracts over five-plus years, moves that looked somewhat questionable even at the time, but not surprising for the Mike Ilitch-led Tigers.
It would be an overreaction to pin the finality of the Tigers’ collapse on Zimmermann, as it probably occurred before he even joined the team, but there may not be a better representative of this ending. While plenty of low-cost, low-tier starters have come and gone through Detroit, Zimmermann is the one mainstay symbolizing the current state of the team.
Entering year four of his five-year contract, the veteran righthander will again attempt to reclaim something close to the form he displayed in Washington. Before joining the Tigers, Zimmermann was coming off of five consecutive seasons of an ERA under 4.00 and at least 160 innings pitched, but neither of those marks have been matched yet in Detroit. His trade value is negligible at this point, and the team is not projected to compete, but a turnaround would still be nice to see.
Falling off a cliff
Pick a number and Zimmermann has been worse in that area since signing with the Tigers. From 2011 to 2015, Zimmermann was extremely reliable with the Nationals. In D.C., he averaged 194 innings per season with a 3.14 ERA and 1.14 WHIP. With Detroit? Just 132 innings a year with a 5.24 ERA and 1.41 WHIP. His strikeout rate has gone down from 7.26 per nine innings to 6.35, while walks have risen from 1.69 per nine to 2.18, and home runs have doubled from 0.80 to 1.61 per nine innings.
The reasons for these spikes in the wrong direction are clear. Opponents have recorded a hard hit rate of 35.8 percent since Zimmermann joined the Tigers, up from 27.8 percent in D.C., and an increased fly ball rate has driven his home run numbers significantly higher. His BABIP has risen as well, from .290 to .310, which could indicate some misfortune, but could also represent a pitcher who is being hit hard on a more consistent basis.
What has changed is perhaps what is most crucial to any pitcher. Zimmermann has seen his fastball velocity fall from 94.6 mph in 2014 to 92.5 mph in 2016 to 91.7 mph last season. Perhaps accordingly, his fastball usage rate has fallen from 70.3 percent in 2014 to only 43.0 percent in 2018, but his secondary pitches are not doing enough to keep him afloat.
One big question: Can Zimmermann build on his 2018 strikeout rate?
All of this sounds like bad news, and not like a pitcher who should be close to the top of any team’s rotation, but the Tigers do not have the most seasoned pitching staff right now — and injuries haven’t helped. Though Zimmermann was not very good last season, he did post his best strikeout numbers in five years. A 20.0 percent strikeout rate in 2018 was better than all but one of his full seasons with the Nationals.
The underlying metrics support the numbers as his best since 2014. A 81.0 percent contact rate was the second-best result result of his career, and his 9.1 percent whiff rate was the second-best as well. Zimmermann has never been a heavy swing-and-miss pitcher, but it was encouraging to see him improve in this category.
Pitch mix was a definitely part of this improvement; as mentioned above, Zimmermann’s fastball usage has consistently decreased over the past few years. In its place has been an increase in sliders, a pitch that has generated whiff rates north of 15 percent throughout his career. Throwing more sliders is not the perfect solution, but it does yield stronger results than his other pitches.
Declining velocity is a concern, and is likely not an anomaly given Zimmermann’s multiple injuries since joining the Tigers. However, his change in pitch mix shows a willingness to evolve, which is important when the status quo is no longer working. The days of sub-3.00 ERAs are probably well behind him, but if Zimmermann can continue to induce some swings and misses, he could finally enjoy some success in Detroit.