Should We Be Concerned About Marcus Stroman?
Marcus Stroman was the Blue Jays best starting pitcher last season and there were high hopes for him heading into 2018. Stroman himself sets high expectations for his performance and he said before that season that he wants to be considered among the best pitchers in baseball. Things have not gone according to plan to start the year.
Through 4 starts Stroman has averaged just 5 innings per outing and has an unsightly 8.55 ERA. He missed most of spring training with shoulder inflammation so it begs the question as to whether this is rust from not having a proper spring to prepare, or worse yet, a lingering shoulder injury that could lead to time on the DL or surgery.
It's not all bad news for Stroman to start the season. He is striking out a career high 21.7% of batters faced. He is also generating an insane 69.4% groundballs. The extreme amount of groundballs has allowed Stroman to give up just 0.90 HR/9, despite surrendering an unusually high 20.0% HR/FB. His 4.48 FIP and 3.94 xFIP suggest he has suffered quite a bit of poor luck.
Looking at the luck based numbers confirms that he has been the recipient of quite a bit misfortune. He has allowed a.350 BABIP against that is far higher than his career rate of .307. However, the bloated BABIP can't be entirely blamed on bad luck. His xwOBA on batted balls has been .465. He has given up a lot of hard contact and might actually be lucky he hasn't given up more hits.
The most eye popping luck stat is his 46.8 LOB% (!!!!!). This is the highest mark in baseball among pitchers with at least 20 innings pitched. There is simply no way this will continue, if it were to, it would be the lowest mark in baseball history. The low LOB% has to do with poor timing of hits and has little to do with his talent. Expect that number to regress toward the league rate of 73% and for his ERA to regress with it.
One thing that may also be contributing to his low LOB% is his lack of double plays. This season he has managed to convert only 8% of his double play opportunities. Last season he converted 22%. 8% is a very low number for a pitcher who induces nearly 70% groundballs. I expect Stroman to induce more double plays going forward and that alone should do quite a bit to help his numbers normalize.
To a lesser extent Stroman's 20% HR/FB could be considered bad luck. He has always given up an unusually high HR/FB rate so we can't just write it off to chance. Considering he has a very high hard hit rate and his xwOBA confirms that, there's a good chance he has earned that 20% HR/FB.
As you can see, a lot of the things that have contributed to his poor start are stats that are out of his control. However, one thing that is in his control, is his control. So far, it has been bad. He has walked 14.4% of batters faced, more than double his career rate. Stroman simply isn't putting the ball where he intends to and it's leading not only to walks, but lots of hittable pitches. Looking at his numbers it's safe to say the biggest culprit is his lack of command. He had really good control in the past so if that comes back I'd expect him to be fine. The strikeouts are up, the groundballs are up, and once he gets his control back he should be putting the balls in places where it's more difficult for hitters to make hard contact against him.
For now, I'm willing to give Stroman the beneift of the doubt. He has been an excellent pitcher in his 4 year career leading up to this season and 4 poor starts shouldn't change that. He may just be dealing with shaking off the rust after missing spring training. If someone were worried about Stroman it would be hard to blame them though. Yes, much of his high ERA has to do with things beyond his control and we should expect positive regression in those areas. However, there are definite red flags that point to it being more than bad luck. The control issues are concerning, even more so considering he was dealing with a shoulder issue before the season started. After the offseason arbitration hubub, Stroman likely feels like he has to prove himself. Is it possible that there is still lingering pain in his shoulder and he's pitching through it? It may explain why a pitcher who once had excellent control suddenly can't find the zone. We all know Stroman pitches with a chip on his shoulder, let's hope there's not also tendon damage on it.
