Andrew Miller has struggled through his first four appearances of the 2021 season with the St. Louis Cardinals. While it is still very early in the season, and Miller could certainly turn things around, there are several early warning signs that he could be in for a difficult season.
To begin with, Miller’s velocity has dropped at the beginning of this season. The southpaw is averaging just 87.8 miles per hour on his fastball, which has continued a decline that started after the 2016 season, when his fastball average 95 miles per hour. His fastball velocity peaked in 2012 at 95.8 miles per hour, and stayed in the 95 range until the 2017 season where it began dropping by nearly one mile per hour each season. However, the steepest part of his velocity decline began in the 2020 season when his fastball velocity dropped to 89.6 miles per hour after averaging 92.4 in the previous season. This is a significant drop, and it appears to have continued this season.
This is dangerous for Andrew Miller, since 87.8 miles per hour is simply too slow to be a reliable pitch without pinpoint accuracy. Kyle Hendricks has been able to survive, and even thrive, in the majors with a fastball that average 87.4 miles per hour in 2020. However, Hendricks has a career walk rate of 5.4% while Miller has a career walk rate of 10.6%. Thus, it appears that Miller does not have to necessary control to thrive despite a low fastball velocity.
Another problem with this is that Miller throws just two pitches - a fastball and a slider. Thus, with a slower fastball and only average control, Miller will have to rely more on his slider this season.
However, this drop in velocity has also effected his slider which has dropped from 80.1 miles per hour to 78.7 miles per hour so far this season. This pitch peaked at 86.1 miles per hour in 2013, and was sitting at 84.3 miles per hour in 2016, when his velocity decline really began. Now that his velocity has dropped, Miller will have to trade sharpness for extra movement. When his slider was sitting at 84, he got less movement, but it was sharper due to the velocity. Now, his slider will need to maintain its effectiveness with its extra movement, and this is something that is not guaranteed. However, Miller had excellent results with his slider in 2020 (.148 wOBA), after allowing a still solid .278 wOBA against the pitch in 2019.
However, since 2018, Miller’s fastball usage has dropped from 42.4% to 38.2% to 30.2% in 2020, and thus far in 2021, just 26.4% of Miller’s pitches have been fastballs. If this trend continues, Miller will need to rely heavily on his slider and use his fastball to keep hitters off balance.
This is a strategy that can work, but for a former power pitcher who is nearly 36 years old and has lost his power, it remains to be seen if he can continue to have success with his fastball and slider combination. If he struggles, however, then it will be time for Genesis Cabrera to step up and become the primary left hander out of the ‘pen. The 24-year-old has the swing and miss stuff, but he needs to improve his control. However, if he is unable to do this, then it could be a long year for the Cardinals against left handed stars, as Tyler Webb is solid at best, but certainly not somebody who is going to shut down left handed mashers. Thus, it would be great for the Cardinals if Miller could retain his effectiveness, but it may be Genesis Cabrera who takes on some added responsibility this season.