Depending on how you want to look at it, Jimenez did or did not pan out as the Rockies’ ace. He did deliver the Rockies’ greatest season by a pitcher in 2010. That season, he threw the Rockies’ only no-hitter and he went on to go19-8 in 33 starts with an ERA of 2.88 with 214 strikeouts in 221.1 innings. He is also the only Colorado pitcher to start in the All-Star Game.
The issue is he was only the Rockies ace for three-and-a-half years before struggling in the first half of the 2011 season … which led to him being traded to Cleveland.
Had he been able sustain his dominance over multiple years, I would have declared him an ace. However, I will say that Jimenez and Pedro Astacio are the closest the Rockies have come to having a true ace.