MLB Hot Stove: Rockies sign lefty reliever Mike Dunn to three-year deal

The contract will pay Dunn a total of $19 million

The Rockies are not done spending this offseason, even after signing Ian Desmond to a five-year contract worth $70 million.

Colorado has agreed to a multiyear contract with veteran left-handed reliever Mike Dunn. The deal will guarantee him nearly $20 million.

Mike Dunn's deal with the Rockies is done: Three years, $19 million.

— Buster Olney (@Buster_ESPN) December 15, 2016

Dunn, 31, has spent the last five seasons with the Marlins, with whom he had a 3.63 ERA (107 ERA+) with 289 strikeouts in 265 innings. This past season Dunn pitched to a 3.40 ERA (116 ERA+) with 38 strikeouts in 42 1/3 innings around an elbow issue.

Mike Dunn is the newest member of the Rockies' bullpen. USATSI

A quality lefty reliever is a necessity in the NL West, as both the Dodgers (Corey Seager, Adrian Gonzalez, Joc Pederson) and Giants (Brandon Belt, Brandon Crawford, Joe Panik, Denard Span) employ very lefty heavy lineups. Dunn has held left-handed hitters to a .228/.309/.330 (84 OPS+) batting line in his career.

The Rockies have a dynamite position player core led by Nolan Arenado, and they finally appear to have some young starters to build around as well. Jon Gray and Tyler Anderson both impressed in 2016, and Jeff Hoffman and German Marquez represent the next wave of arms.

The bullpen is still a major problem -- Colorado's relievers had a 5.13 ERA and 1.47 WHIP in 2016 -- and figures to be the focal point the rest of the winter for the Rockies. Dunn might not be their last free agent reliever signing.