Its easy to over-react to the news that Scott Baker is having a hard time getting loose and experiencing some arm pain. But in some ways, its impossible not to overreact. Last year the Twins went into the season with what looked like a deep rotation after a spring competition among six veteran starters. They had their sixth starter, Kevin Slowey, in the bullpen and Anthony Swarzak as a swing man behind him. In addition they had Kyle Gibson apparently almost ready at AAA. That depth eventually evaporated and the Twins crash the last two months of the season is probably attributable to most of the rotation being on the DL.
This year, the Twins do not have any depth. The Twins sent last year's rule 5 guy, Scott Diamond, to the minor leagues this morning and then watched this year's rule 5 guy, Terry Doyle, get lit up by the Pirates. Swarzak came in to relieve him and did better than Doyle, but it was still not good. Liam Hendricks gets a start tomorrow, but he does not look like nearly as strong a prospect as Gibson was last year. After that, there are some folks who previously failed as starters competing for bullpen spots. Its possible they can stretch out Brian Duensing, but that leaves the bullpen with another hole.
In short, the Twins don't really have a solid sixth starter. If Baker or any of the other guys in the rotation can't pitch, its likely the Twins will end up holding auditions among a group of questionable replacements. It could turn into a rough spring start while they sort things out.