Another blown save last night gives Kenley Jansen one more than than he has had all season last year. And its still April. This is going to be a long season for the hard throwing closer.
Even the smallest change in mechanics can make the biggest change in performance. When a pitcher gets injured and does not address the underlying issue, the body adjusts to avoid feelings of discomfort or instability and that can lead to a change in command and speed of a pitch.
Jansen was held from pitching in March 2018 due to right hamstring "tightness". The hamstring which attaches to the pelvis and acts on the hip can be an indicator of guarding of that hip. In Jansen's case, his right hip is his drive leg, where he initiates his pitching sequence. Probably not a joint you want having problems with when you are driving that 6'5", 275 lbs frame. Hamstring length and flexibility is usually what is rehabbed, but it is what the hamstring is guarding that I would worry about. Don't expect Kenley to return to true all star form until he addresses the underlying source of the problem.
The Injury Analyst is a blog dedicated to not only explaining injuries that have occurred, but predicting and highlighting future injury risks for professional athletes. You can email us at firstname.lastname@example.org
Note: I have not seen the subject of this article personally in clinic, rather all views and opinions of the author have been made based off of video footage of the athlete. This article is not meant as a diagnosis or a treatment plan.