The mini-trend this year seems to be teams shifting relievers to the rotation in recognition of the fact that a 180-inning league average starter provides far more value than even a high-end reliever. Daniel Bard, Chris Sale and Neftali Feliz have all made the switch to the rotation this year, and early returns are positive.
With those experiments in mind, here are six other relievers around baseball who I think could help their clubs more by assuming starting roles:
It's great that Chapman has punched out 15 of 27 batters faced this season, but he was a lifelong starter in Cuba and has the off-speed pitches to handle starting in the U.S. if he was just given the chance. His fastball might only sit at 93-94 mph as a starter, but it would likely cause less stress on his arm if he's not airing it out on every pitch, and he has the slider to miss plenty of bats. Arms like this are often forced to the bullpen by injury or lack of command, but Chapman hasn't been hurt (beyond shoulder soreness in November that disappeared with rest) and has never been given the opportunity to refine his command in longer outings. The Reds owe it to themselves to try him as a starter.
I'm having a hard time understanding why Atlanta keeps pushing Randall Delgado and Julio Teheran into open rotation spots when Medlen, who if nothing else is more ready for major league duty, is right there in their bullpen. Medlen would probably pitch with a solid-average fastball as a starter but could run it up to 94, and with a plus changeup and solid-average curveball should be no worse than a back-end starter. It helps that he's a great athlete, a converted shortstop who can really field his position, and that he throws a ton of strikes.
Ross is only in the big leagues right now because Texas had a spot in its bullpen; long-term, he's got the weapons and the mental approach to start. Everything Ross throws has movement, and he seems to be able to sink, slide or cut his pitches at will. His fastball, 90-93 in the 'pen, would likely be more 88-91 in the rotation, but that fastball, plus a hard cutter/slider and a solid-average changeup would be plenty for a left-handed starter with the ceiling of a solid No. 3. Of course, Ross' challenge is that Texas' bullpen contains two former starters, Alexi Ogando and Scott Feldman, who would be in many other clubs' rotations as well.
This will never happen, and perhaps it shouldn't, as Guerra was extremely wild as a young starter, leaving the rotation after his age-21 season and eventually finding control in the bullpen. But unlike most short relievers, Guerra has a full repertoire -- fastball, cutter, slider and curveball -- and has shown the ability to dominate hitters on both sides of the plate. At 6-foot-1, 200 pounds, his body isn't ideal for a starter, and he'd have to show he can pitch effectively at 90-91 rather than 92-94.
Johnson works primarily with his fastball as a reliever but has a three-pitch repertoire that includes a changeup with hard late tumble in the upper 80s and a hard downer curveball in the 78-82 mph range, both of which he locates for strikes. At 6-6, 240 pounds, he has a workhorse starter's build, and he's wasted if he's just used as a capital-c "Closer" who records only three outs at a time, and only in save situations. (He did throw a lot of longer outings last year when he wasn't the designated closer, with 91 innings across 69 appearances, including 22 outings when he faced seven or more batters.) My one concern is that he has never missed a ton of bats as a reliever, and that rate is typically lower for starters than it is for relievers.
I'm on the fence about Crow's ideal role; he was a very effective starter at the University of Missouri (despite a hook in the back of his delivery that scared some teams off him), and he ended up in the 'pen in large part due a botched negotiation when he was drafted by Washington in 2008, a process that led to him missing a year and not debuting in pro ball until October 2009. He's built up enough arm strength now that he should be able to maintain above-average velocity all year as a starter, with two above-average breaking balls. But what he doesn't have is a strong pitch to retire left-handed batters, who hit .311/.381/.538 off him in the majors last year, due to a changeup he seldom uses because it has no action on it, rendering it more like a below-average fastball. If he had that weapon -- a better changeup or even a splitter -- he could be a strong mid-rotation starter for a team that could really use another high-quality arm in its rotation.