This article is part of our Fantasy Baseball Injury Report series.
Tatis was a surprise addition to the weekly injury report after suffering a shoulder injury late Monday night. The Padres outfielder hit the ground after a failed swing attempt and was in visible pain and discomfort. He was helped off the field by a member of the San Diego medical staff and was later diagnosed with a left shoulder subluxation.
Despite multiple stabilizing structures, the shoulder is one of the most common joints forced out of alignment. An injury that results in joint displacement can be classified as a subluxation or a dislocation. A subluxation occurs when a joint is temporarily displaced and is also known as a partial dislocation. The joint is often reduced, or returned to its normal alignment, naturally and almost instantaneous by the surrounding stabilizing structures, including muscles and ligaments. A true dislocation occurs when the displacement of the joint is complete. When a dislocation occurs, the injured athlete often needs assistance by a medical professional to return the joint or articulation to its normal positioning.
Regardless of classification, the primary concern with a subluxation or dislocation involves the surrounding soft tissue structures. For a joint to come out of alignment, some sort of damage to ligaments, muscle, or cartilage must occur. Once the structures are injured or overstretched the stability of the joint is compromised, and a subsequent subluxation or dislocation is more likely. The Padres confirmed that this is not Tatis' first subluxation and that he has experienced several partial dislocations in the