Rockies reliever Mike Dunn will undergo season-ending surgery on his left A/C joint in the coming weeks, Patrick Saunders of the Denver Post reports.

The injured Dunn last took the mound July 3, when he allowed at least one earned run for the eighth time in 25 appearances this season. The left-hander wound up throwing 17 innings for the Rockies this year, logging an unsightly 9.00 ERA with more walks (18) than strikeouts (12). It’ll go down as the second straight rough season for the 33-year-old Dunn, formerly an effective reliever with the Marlins.

In December 2016, on the heels of his Miami tenure, the Rockies added Dunn on a three-year, $19MM guarantee, though that signing has not worked out to this point. The Rockies followed that up by spending big on fellow relievers Wade Davis, Bryan Shaw and Jake McGee last winter, but all of them have joined Dunn in struggling this year. Including Dunn’s $7MM, Colorado will owe the four of them a combined $42MM in 2019.