Samuel Deduno, RHP
Two things killed Deduno in 2012: allowing one in every five fly balls to leave the park, and being unable to hit his spots. He had a decent fastball and a good slider, but his changeup wasn't of much use and his primary breaking ball, his curve, wasn't terribly effective, either. Luckily, Deduno's home run rate is likely to drop going forward. Looking at balls in play, only 20% were flies compared to 58% being grounders. That ugly 21.3% HR/FB ratio is going to take a dip.
The Oracles seem to agree. Bill James has Deduno pegged for 4.06 ERA in 124 innings. Of course, he also has Deduno down for 5.5 walks per nine innings. At least that's still an improvement over last season.
If Scott Diamond is ready for Opening Day, he'll team with Kevin Correia, Mike Pelfrey, Vance Worley and hopefully Kyle Gibson to form the Twins' strarting five. On the outside looking in will be pitchers like Liam Hendriks, Cole De Vries, Brett Hermsen, Ryan Pressly, and even Nick Blackburn.
All of which means that Deduno has plenty of competition. It's hard to say where he is on the depth chart for MLB starters, but it's a sure shot that he's not in the top five currently and that at least two of Hendriks, De Vries, Hermsen, and Pressly (who are all on the 40-man roster), Blackburn, and one of the top five would all have to have something go wrong in order for Deduno to get an opportunity to go north.
It seems likely that he'll see some time with the Twins at some point this season, but it seems unlikely right away.
Chances of making the roster: Unlikely.