Matt Belisle didn't arrive in Denver as a high-priced savior; instead, he was a former starter from Cincinnati who reinvented himself as a high-frequency weapon out of the bullpen, and for six seasons, he was the rubber-armed heart of the Colorado relief corps.

He reached a definitive level of efficiency in 2010, posting a career-best 2.93 ERA and a 1.087 WHIP over 92 innings, and the year after, he had an atypical 10-4 record for a middle reliever. 

In 2012, Belisle led the National League by appearing in 80 games, a grueling workload that would have broken most arms at altitude. He functioned as the ultimate bridge to the ninth inning, utilizing a sharp slider and a heavy sinker to navigate the most dangerous hitters in the division. He finished his run in Colorado with 392 appearances, a total that places him among the most tenured pitchers in the team's history. His career 3.97 strikeout-to-walk ratio with the club remains a benchmark for relievers trying to survive the thin air without giving up walks.

He stayed with the organization through 2014, eventually returning for a brief second stint in 2018 to provide veteran leadership to a young, postseason-bound squad.

The arrival of Adam Ottavino in Colorado in 2012 was a quiet transaction that eventually reshaped the backend of the Rockies' bullpen for the better part of a decade. Claimed off waivers from St. Louis, the right-hander brought a lanky frame and a sweeping slider that seemed specifically designed to frustrate hitters in the thin mountain air. While he began his professional journey as a starter, the move to the high country saw him fully embrace a relief role,

He established himself as a model of durability over his first three years, appearing in 75 games in 2014 alone and maintaining a professional poise that put him in the conversation for the closer’s role. However, his story took a difficult turn in early 2015; just as he was poised to take over the ninth inning, a significant elbow injury required Tommy John surgery, forcing him to miss the remainder of that season and a large portion of 2016.

Ottavino didn't just come back; he authored a franchise-record 37 consecutive scoreless appearances spanning the end of 2014 and his return in 2016. His performance reached an elite level of efficiency during the 2018 campaign, a summer where he served as the primary set-up man for a playoff-bound squad. That year, he posted a 2.43 ERA and struck out a staggering 112 batters in just 77.2 innings, setting a then-Rockies record for strikeouts by a reliever.

The story in Colorado concluded following the 2018 season when he signed with the New York Yankees as a free agent. He departed as one of the most statistically significant relievers to ever wear the purple pinstripes, leaving behind 17 saves and nearly 500 strikeouts as a Rockie.