Doug Fister (5-1, 3.62)
When Fister first made the major leagues with the Mariners in 2009, he wasn't really a special pitcher. He didn't strike many hitters out, he didn't get a lot of ground balls, and he gave up a ton of homers. The next season, he cut down on the home runs by a ton, but an increase in hits left his ERA at a nearly identical 4.11 after having a 4.13 in his rookie season.
Then came 2011, where Fister started putting things together. He was still limiting home runs, he started suppressing hits, and it led to a 3.33 ERA. But, he was being backed up by the woeful Mariners offense, so his record was a measly 3-12 as the July 31st trade deadline approached. The Tigers were not turned off by that W/L record and acquired Fister and reliever David Pauley for outfielder Casper Wells, reliever Charlie Furbush, third base minor leaguer Francisco Martinez, and a PTBNL, which turned out to be minor league pitcher Chance Ruffin.
Upon joining the Tigers, Fister added the final piece of the puzzle that had been eluding him in his short career: the strikeout. With the Mariners he sat at 5.49 K/9, but for the remainder of the season with the Tigers, it jumped to 7.29. Since then, his K/9 has consistently been above 7.0, showing that whatever he learned upon joining Detroit has stuck with him. Additionally, his ground ball percentage has skyrocketed, sitting at a career-best 56.7% this year. For reference, last year saw only 5 qualified starting pitchers that had a GB% higher than Fister's current rate. All of this has transformed Fister from a middling pitcher to one of the best #3-4 starters in the league.
Fister throws a 2-seam fastball, 4-seamer, change-up, curveball, and cutter. His 2-seamer and change-up are both above-average pitches according to FanGraphs, while his 4-seamer and curve are average and the cutter is pretty bad, but it's also the pitch he throws least often. Remember, he does not allow many homers, he gets a ton of grounders, and he will not walk anyone. This doesn't sound promising for the Twins.
P.J. Walters (2-5, 5.69*)
* 2012 stats
Walters makes today's start as the Twins seem to return to last year's plan of throwing everything at the wall and seeing what sticks. They've already discovered that Liam Hendriks, Pedro Hernandez, and Vance Worley aren't cutting it right now, and with Cole De Vries struggling in the minors and Kyle Gibson "not ready" for the majors, they've turned to Plan... uh... just pick a letter after E, I've lost count.
Walters made his Twins debut last season on May 12th, and for a while it seemed like he was a godsend. In his first 4 starts after being called up, he had a 2.96 ERA with a complete game win against the Chicago White Sox in start #3. However, his next three starts were a disaster as he allowed 13 runs in only 9 1/3 IP, which culminated with him exiting his start against the Philadelphia Phillies where he gave up 4 runs without recording a single out. Afterwards, it was determined that Walters had right shoulder inflammation, and he sat on the disabled list for nearly 3 months.
When he came back, Walters' struggles continued as he gave up 16 runs in 14 innings in his first three starts off the DL. But, he rediscovered his form in his final three starts by allowing only 7 runs in 16 innings, including back-to-back solid starts against the Tigers to end the season.
Compared to the rest of the pitching rotation, Walters actually gets a decent number of strikeouts. However, he's been unable to carve out a regular role on a major league squad because he gives up too many hits and his home run rate is nearly double the major league average. Scott Baker was nicknamed "Moon Shot Scott" by some Twins fans, but you should realize that Baker was actually pretty stingy (1.16 HR/9) upon being compared to Walters (1.92 HR/9). Again, against this Tigers offense, this game does not look promising.
Walters throws a 4-seam fastball, a low-70s slurve, a 2-seamer, change-up, and possibly a cutter (pitchF/X does say he has a cutter but it's a very small cluster of pitches). His best pitch is that slurve as it features a ton of horizontal movement, and pretty much every other pitch of his is terrible save for the psuedo-cutter, likely because they all become gopher balls.
Fun fact: There is no "J" in P.J. Walters' name. His full name is actually Phillip DeWayne Walters.