Aroldis Chapman, the flame throwing closer for the New York Yankees, was placed on the disabled list with left rotator cuff inflammation and is expected to be out for at least the next month. The good news is that an MRI came back negative, meaning that likely Chapman does not have a complete or partial tear of any of the four rotator cuff muscles (supraspinatus, infraspinatus, subscapularis and the teres minor).
Let me get a little medically technical here and describe exactly how the rotator cuff muscles work within the shoulder joint. The rotator cuff is actually a group of (the aforementioned) four muscles whose goal is abduct (move away from the body) the humerus (supraspinatus), externally (infraspinatus and teres minor) and internally (subscapularis) rotate the arm. Collectively the rotator cuff muscles are vital in moving the shoulder and maintain glenohumeral joint (shoulder joint) stability. These muscles originate from a bone in your back called the scapula, and connect to the head of the upper arm bone (humerus). The easiest way to think of the shoulder joint is to think of a golf ball sitting on a golf tee. Where the golf ball is the head of the humerus, and the golf tee if the shoulder joint.
Now imagine if the shoulder joint, or the golf tee in our comparison, were weakened or damaged in some way. This could possibly cause pain, instability, loss of strength, and even loss of certain movements depending on which part of the shoulder joint is damaged. In the case of a rotator cuff injury, this can not only cause pain and weakness, but also loss of the ability to raise the arm away from (and sometimes above the head) the person’s body. In terms of a pitcher, this can cause them to have decreased velocity and command for their pitches.
The supraspinatus is the most commonly injured muscle of the four rotator cuff muscles. A doctor can help to assess which of the four muscles is injured by having the patient/athlete move the arm in various directions. If certain movements cause pain or are unable to be performed, then the muscle corresponding to the movement is often involved. The best way to identify if a muscle is injured is to get an MRI of the shoulder. In Chapman’s case, his MRI was reportedly negative, meaning that there were likely no major or partial tears of any of the 4 rotator cuff muscles as well as the several other muscles that make up the shoulder joint. Based on reports, it appears that Chapman has rotator cuff inflammation, which often takes 2-8 weeks to return from, and often involves rest, strengthening exercises, anti-inflammatories and sometimes even a corticosteroid injection (typically using a sub-acromial approach). Hypothetically if there were any partial or full tears of one of the muscles, he would have potentially needed arthroscopic surgery. Appropriate rehab takes about 3-8 months, depending on the severity of the tear, to return from.
Chapman has not been as rock solid as expected when they gave him an $86 million contract in the offseason. With that much money invested, the Yankees are going to be careful with their stud closer. Based on the past couple of outings that Chapman participated in, I believe he has been dealing with this issue for at least a week or two. Over has last 2 outings (4 outs), Chapman has given up 6 hits and 4 ERs leading to a 3.55 ERA for the season. Expect Delin Betances, equally as dominant as healthy Chapman, to serve as the closer. If Betances is available in your league, which would be very surprising, then go grab him now.