This wasn't supposed to be a competition until the Twins re-signed Carl Pavano to give them six capable starters for five rotation spots. Francisco Liriano figures to be the ace, with Pavano and Scott Baker sliding in behind him. After that it's anyone's guess.
Nick Blackburn, 29, has the most experience of the remaining options with 92 starts in the last three seasons in Minnesota. But after a promising start to his career the righty struggled in parts of 2010 and finished with a 5.42 ERA. Blackburn has a good combination of pitches, but is not overpowering and tends to give up big hits (career 1.2 HR/9). Still, he's signed through at least 2013 so the Twins can't exactly sit him on the bench.
Kevin Slowey, 26, has spent his entire career as a starter for the Twins, making 82 starts over parts of four seasons. But although he's 23-9 in the last two seasons, the righty's 4.41 career ERA and 1.28 WHIP leaves much to be desired. Slowey was the beneficiary of huge offensive support (7.4 runs/game in 2009 and 6.2 runs/game in 2010) and he doesn't really have a single plus pitch, so it's debatable he should ever have been in the Twins rotation in the first place.
Brian Duensing, 28, made his major league debut for the Twins in 2009 and was impressive in nine starts, compiling a 3.64 ERA over 84 total innings. The lefty split time between the rotation and the bullpen in 2010, but was still good enough to pitch 130 innings with a 2.62 ERA and 1.22 WHIP. Duensing doesn't have phenomenal stuff, but he's proven that he's competent enough to be a back-end starter for a long time.
The Twins also have a collection of minor league options that could spot start or maybe join the rotation later in the season, including Deolis Guerra, Jeff Manship, Ryan Mullins, Glen Perkins and Anthony Swarzak.
Duensing figures to have a firm grasp on the No. 4 spot and, while neither Blackburn nor Slowey inspires much confidence, Slowey at least has a recent history of success. This will be a very difficult decision for manager Ron Gardenhire to make, and one he's hoping will be made for him via an injury or a trade.