Before breaking down this week's round of injuries I want take this opportunity to review some basic medical terminology that will be helpful for the remainder of the season. To start there is a difference between a sprain and a strain. A sprain occurs when a ligament, the tissue connecting bone to bone, is injured. Ligaments provide stability and protection to joints during movement. On the other hand, a strain occurs when a muscle is damaged. A strain can occur in the belly of the muscle or the connective tissue of the muscle, better known as a tendon. Both sprains and strains vary in their recovery time and cannot be treated equally.
The grading system for both these injuries remains the same. Both sprains and strains are graded on a scale dependent on the amount of damage sustained. A Grade I injury is the least severe and is often referred to as a minor sprain or strain. Grade 1 injuries are accompanied by micro-tearing of the tissue with little to no loss of function. A Grade 2 injury is often referred to as a partial tear as actual muscle or ligament fibers are torn. These injuries come with a longer recovery window and significant impairment. A severe Grade 3 or 4 injury means that the tear is complete, resulting in a total loss of function. More often than not these injuries require surgical intervention and a substantial amount of rehab and recovery.
Puig is the reason for the above-mentioned analysis. The inflammatory outfielder suffered a thumb injury when sliding into first base during Saturday's win over the Giants. He did not play Sunday and subsequent testing revealed the extent of the damage. The Dodgers reported that Puig has suffered a strained ligament. Based on the previous breakdown we know the injury is actually a sprain not a strain. Fortunately the severity of the injury appears minor and Puig is considered day-to-day. The team will treat the associated pain and swelling and if they subside Puig should return to the lineup. He does have a history of thumb injuries and won't need an adjustment period to get accustom to the protective brace he will likely wear. However if his grip strength is at all affected, expect a dip in his power numbers.
Mariano Rivera manned the Yankees' closer role for 17 seasons and made just four trips to the disabled list. Two weeks on the job and Robertson has already made his first. Robertson suffered a groin injury when completing a save over the weekend and was sent for a MRI after the pain persisted. The imaging revealed a Grade 1 strain. While not as significant as a shoulder or elbow injury, lower extremity issues can be very problematic. Over half of the required kinetic energy to successfully pitch a baseball is generated below the waist. If the lower extremity is limited by injury, a pitcher risks a drop in velocity and change in biomechanics. A change in mechanics makes a pitcher more susceptible to other injuries and must be properly managed.
For Robertson, a strained groin directly affects the lateral motion in his pitching mechanics, in particular the motion known as adduction. Adduction occurs when the leg is pulled toward the midline of the body and is carried out by the muscles of the groin. A strain to the area would limit Robertson's ability to smoothly transfer his body weight during the acceleration and follow-through phases of each pitch. Fortunately the strain is minor and the 15 mandated days should be enough, barring any setback. In the meantime Shawn Kelley will take over as the interim closer and should be owned in all formats.
Cole Hamels: Hamels completed a rehab assignment Sunday surrendering two runs on three hits and no walks over four innings. The former World Series MVP is slowly working his way back from a minor case of biceps tendinitis. He will likely need several additional rehab appearances before he returns to the active lineup but his return is on the horizon.
Will Middlebrooks: Middlebrooks has been placed on the 15-day DL after suffering a Grade 1 strain of his right calf. While the third baseman does have a small history of hamstring problems, they've all been on the opposite leg and he should be able to return shortly. Keep a close eye on his progress through rehab to get a more accurate estimate on when he will be back.
Jurickson Profar: The Rangers second baseman remains multiple weeks away from returning but he has returned to fielding work. It's a nice step forward for a player that has plenty of upside.
Wilson Ramos: The Washington catcher underwent surgery on his fractured hamate bone and is expected to miss four weeks. In the surgery, the hamate is actually removed and will no longer be an issue, allowing for a relatively quick recovery. Hamate surgery has been previously performed on such sluggers as Pablo Sandoval, David Ortiz, Dustin Pedroia, and Ken Griffey Jr. and all returned to play at a high level. An initial drop in power should be expected but Ramos should be fine when he returns.
Brian Wilson: The Bearded One has made progress in his rehab for an inflamed ulnar nerve. The ulnar nerve, as its name suggests, is a nerve that runs the length of the ulna bone. It's vulnerable to injury near the elbow and is what's irritated any time you "hit your funny bone." It's common for nerve complications to arise in players recovering from Tommy John surgery so this isn't overly alarming just yet. However should the nerve issues persist, an additional surgery would be needed that would sideline Wilson for an extended period of time. He recently tossed a scoreless inning at High-A ball and is line to return in just over a week.
Ryan Zimmerman: The Nationals slugger has suffered a wide assortment of injuries in his career including an abdominal strain, hamstring strains, back spasms, and reoccurring shoulder issues. The shoulder problems have once again flared up as Zimmerman headed to the MRI machine over the weekend. Fortunately the tests revealed inflammation but no structural damage. Consider him day-to-day but this is a discouraging sign this early in the season.