Wade Davis injury: Second DL stint cause for long-term concern?

Wade Davis has been placed on the DL for the second time, both for the same forearm injury. Icon Sportswire

When is a forearm strain in a pitcher really just a forearm strain?

The Kansas City Royals hope it’s when your name is Wade Davis.

On Sunday, the Royals announced they were placing Davis on the 15-day disabled list with a Grade 1 (mild) right forearm strain, his second such designation within a month.

In early July, Davis was placed on the DL with a forearm strain and within a week he indicated he was pain-free. He resumed throwing shortly thereafter and was reinstated when first eligible on July 16. Two days later, Davis had his first save opportunity. He secured it with three pitches against the Cleveland Indians. Clearly this forearm strain was no big thing, right? No reason to worry about something more serious, such as a significant tear in the forearm muscle, or, dare we say it, damage to the ulnar collateral (Tommy John) ligament for instance?

Ten days ago there was an easy answer to those questions. Why worry? Davis had converted two saves since coming off the DL, raising his total to 21 of 23 on the season.

Then something changed. Davis struggled in a July 27 appearance against the Angels and a few days later he was undergoing an MRI. The worst was feared. Maybe there was a bigger muscle tear than first suspected. Maybe there was a tear in the UCL after all.

Royals’ manager Ned Yost sensed the level of concern, telling reporters Sunday the MRI revealed only the mild flexor strain but “the elbow looked fine.” In other words, there was no visible damage to the ligament or any other major structure. Despite the decision to return Davis to the DL, the move is retroactive to July 27 and the Royals seem hopeful Davis can again return when eligible.

But how concerning is this sequence of events, really?

On one hand, the relatively quick bounce back Davis had earlier this month -- combined with his level of performance upon his return -- is encouraging, as is the reportedly clean MRI. Davis experienced a forearm issue late last season, but after the team shut him down for seven days, he was able to return. Although he pitched well upon his return, according to Yost, Davis struggled with the forearm throughout the postseason. The decision to send Davis to the DL in early July was partly a proactive move to prevent the issue from lingering.

Yet, on the other hand, here is Davis on his second DL stint this July with the same ailment. It is either lingering … or worsening. It’s normal to worry about a flexor muscle strain as a precursor to problems with the UCL because:

(A) Anatomically they both sit on the medial (inner) side of the elbow and are subject to similar stresses and

(B) There have been prior cases where a flexor muscle strain was the initial culprit but ultimately the ligament failed.

Since the UCL and the flexor muscle group are both subject to the significant tensile stress placed on the medial elbow during throwing, they are both vulnerable to breakdown over time. Even if there is no visible damage on MRI, the wear and tear of the repetitive pitching motion may be taking its toll on these structures at the microscopic level and can be enough to affect performance.

In an odd coincidence of timing, pitcher Homer Bailey returned to the mound for the Reds on Sunday, his first outing since undergoing Tommy John surgery in 2015. The prior year, Bailey was diagnosed with a flexor mass injury that initially was thought to not require surgery. After plateauing in his recovery, however, Bailey’s 2014 season came to a premature close and he had surgery to repair his flexor tendon that September. He was able to start the 2015 season but, less than one month in, Bailey was diagnosed with a UCL tear, leading to his second consecutive elbow surgery. On a positive note, Bailey enjoyed a successful return to the mound Sunday but cases such as his are the reason there is anxiety about the recent turn of events with Davis.

At 30 years old, there is no denying that Davis has plenty of mileage on his throwing elbow. His shift to a closer role in the past few years has certainly dropped his innings workload. Perhaps it is that lighter total load that has helped to extend the life of his elbow, at least thus far.

Unfortunately, there is no measure other than function to tell Davis (and the rest of us) whether his elbow will once again cooperate after another brief hiatus or whether there is more grim news on the horizon.