Deeper tiers

None of the most likely candidates for the fourth starter spot -- or fifth starter when Ervin Santana returns -- seem to have helped themselves the past turn through the spring rotation.

Oh, Fernando Romero has opened eyes with his impressive stuff. But he only threw 125 innings last season in Double A  -- a career high -- and staggered to get that many in. I can't imagine the carnage necessary for him to open the season in the majors.

Aldaberto Mejia, who I rated earlier as a Tier One candidate -- had a lackluster three innings in Tuesday's start -- four hits, three earned runs. He also threw a pickoff throw away, adding to my belief that he is the worst fielding pitcher the Twins have had in decades. There are things to like about Mejia, but he's establishing himself as a very frustrating pitcher.

I earlier listed as Tier One candidates Phil Hughes, Mejia and Anibal Sanchez -- Hughes and Sanchez because they have had outstanding seasons in the past, Mejia because he spent most of 2017 in the Twins rotation.

Tier Two was made up of Tyler Duffey, Aaron Slegers and Stephen Gonsalves. I put the latter two in this group because they were actually starting games at the beginning of the exhibition season. But their most recent appearances have come in relief, as have all of Duffey's appearances.

There are other starting pitchers in camp, specifically prospects Felix Jorge, Dietrich Enns and Zack Littell. Along with Romero, they are probably Tier 3 -- less developed, or at least less experienced, than the Tier 1 and 2 guys.

Littell -- who came to the Twins with Enns in last July's selloff of Jaime Garcia -- particularly intrigues me. He lacks the firepower of Romero, but he's got a track record of effectiveness so far in his minor league career -- 19-1, 2.12 for three teams last season, split between High A and Double A. He's continued that effectiveness this spring, but he's only pitched late in games, so he's not facing major league hitters.

None of the Tier 3 guys are serious candidates for the opening rotation unless or until Paul Molitor uses them earlier in games. And I don't think any of the Tier 1 guys are going to take the job and hold it.