Colorado Rockies designate Jorge Rondon for assignment, select the contract of LHP Ken Roberts

The Rockies designated right-handed relief pitcher Jorge Rondon for assignment today and selected the contract of left-handed relief pitcher Ken Roberts, according to Patrick Saunders (tweet). The Rockies immediately called Ken Roberts up to the big leagues. He's on the lineup card tonight against the Padres.

The Rockies claimed Rondon off of waivers from the St. Louis Cardinals in November. The team called him up last weekend after Adam Ottavino went on the disabled list. Rondon's role was supposed to be bullpen depth—every team needs it. But after Rondon failed to record an out last night while giving up eight runs, the Rockies decided that, in addition to a necessity, bullpen depth is also a bit like throwing spaghetti at the wall and seeing what sticks. Rondon's time with the Rockies finishes up with an inning pitched, a 90.00 ERA and an ERA- of 999.

The team's new string of spaghetti is Ken Roberts. The Rockies drafted Roberts in the 25th round of the 2010 amateur draft. From rookie ball to Triple-A since 2010, Roberts has pitched just over 300 innings for the organization with an ERA of 2.37. In his minor league career, he's struck out 6.8 batters per nine innings. Encouragingly, he's been good at limiting walks and home runs, as he's allowed only about two walks per nine innings and has given up 0.4 home runs per nine. If Roberts makes it into tonight's game, it will be his major league debut.

It's interesting that the Rockies chose to recall another bullpen arm, and stick with an eight man bullpen, rather than another position player to fill out the bench. Wilin Rosario might reside in Triple-A longer than we, and he, thought. Others will wonder why the Rockies chose to go with Roberts, who was not previously on the 40-man roster, instead of Tommy Kahnle. It's becoming evident that the only reason Kahnle was on the active roster all of last season was because he had to be. It's unclear what the Rockies plan for Kahnle is, but it is clear that they do have a plan for him. In any case, it's a bit more obvious than the plan for the active roster.