Royals reliever Carlos Estévez will undergo shoulder surgery next week, manager Matt Quatraro tells reporters (link via Anne Rogers of MLB.com). The skipper described it as a “somewhat exploratory” procedure, so there’ll likely be a more defined timeline once the operation is complete. Estévez was diagnosed with a rotator cuff strain in early May and tried unsuccessfully to rehab without going under the knife.

Estévez made his second All-Star team and led the majors with 42 saves last year. That was the first season of a two-year, $22MM free agent contract that looked like a solid investment in year one. Year two goes down as a complete wash. Estévez made one appearance and gave up six runs, punctuated by a Dominic Smith walk-off grand slam, in his only outing.

Kansas City placed Estévez on the injured list after that outing. The initial diagnosis was a left foot contusion which he suffered on a comebacker during that nightmare appearance in Atlanta. Estévez certainly seemed off before that game, though, as his velocity was down during Spring Training and in the World Baseball Classic.

Losing Estévez was one of many issues in a brutal year for the K.C. bullpen. Only the A’s have a higher reliever ERA than the Royals’ 5.09 mark. Their 18.6% strikeout rate is dead last in MLB. Lucas Erceg, their first choice to fill in at closer, has an ERA above 6.00 and has been in Triple-A for the past couple weeks. Alex Lange got some run in the ninth inning between June and July. Steven Cruz has been the preferred closing option of late. Kansas City clearly has a lot of work to do in the late innings.

Estévez will return to free agency when the Royals inevitably decline a $13MM club option in favor of a $2MM buyout. It remains to be seen if he’ll be command a major league contract, which will probably depend on the specifics of the surgery and/or the quality of his stuff when he’s able to conduct a showcase.