While SP prospects can and do contribute out of the pen, I'd like to see us aim to allow Romero to contribute in 2018 as a starter if necessary, through the end of the MLB season and into a potential postseason. As an example, Lance McCullers Jr. was coming off similar low innings and inexperience entering 2015: https://www.baseball-reference.com/register/player.fcgi?id=mccull002lan&type=pgl&year=2015 They started him slowly in the minor leagues, promoted him in May, demoted him for 2 weeks of rest in August, and then let him finish the season in MLB and in the postseason rotation. Wound up with 125 IP in MLB, 35 in the minors, and 6 more in the postseason. The Twins could follow a similar pattern with Romero in 2018, perhaps a little more conservative with a target of 150 IP before any potential postseason innings. Obviously this wouldn't be locked in stone, but if we start out with this template, it is still easy to shift to other plans as the season develops -- leave him in AAA if he's not ready, or shift him to the pen, or shut him down. But if you start out with one of those other plans, it becomes almost impossible to even have the option of Romero starting through September.