Jason Johnson: C-
For someone who was supposed to be the Tigers ace, Johnson came up well short, especially struggling at the end of the season. For a team that was looking for consistency at the top of their rotation, Johnson provided the Tigers with the exact opposite – a good outing followed by a bad, then a stretch a few good ones, followed up with a few bad ones. After watching Johnson all season long, it has become obvious why Baltimore didn't offer Johnson arbitration this past offseason – making him available to the Tigers with no draft pick compensation necessary. Johnson is still under contract for another season, but is by no means guaranteed a spot in the rotation next season.
Mike Maroth: B+
After a rough 2003, Maroth came on strong in 2004 to give what Johnson couldn't – consistency. His ERA was higher than it should have been too, largely due to pitching too deep into some games. Maroth gave the team a chance to win almost every start. A great guy and a clubhouse favorite, Maroth will be welcomed back to the rotation, assuming he's not dealt (an outside possibility) in the offseason.
Nate Robertson: B
Would be higher if not for a late season slide, Robertson came into the year with something to prove, and did just that. He had some struggles at times, but led the team in wins nonetheless. Robertson will probably return to the rotation in 2005, but free agent additions could put his position into question. If the Tigers do make some additions to the rotation, don't be surprised if they possibly try Robertson in a late inning role in an attempt to aide their ailing bullpen.
Jeremy Bonderman: C+
It was an up and down year for Jeremy, still being a very young pitcher in the big leagues. Overanalyzing of his mechanics forced him to struggle at times, but for the final 6 weeks, Bonderman just went out and pitched, and in turn showed why he's one of the top young pitchers in the game. Bonderman will obviously be back in 2005, and his potential is endless – much has been made of the Tigers needing to go out and get a true #1, but they still might have that number one on team already in Bonderman.
Wilfredo Ledezma: B
Ledezma was solid for the 6 weeks he was in the rotation before stepping out due to his innings limit. Ledezma was spectacular at AA Erie, and continued to pitch well in his 2nd rotation appearance for the Tigers. He probably doesn't have the same ceiling as Bonderman does, but should still be a mainstay in the middle of the rotation for the club for years to come.
Gary Knotts: C
After not being expected to do much, Knotts stepped up admirably in replacing Nate Cornejo, before he lost his spot in the rotation to Ledezma when he was sidelined with arm soreness. However, despite Knotts' performance, he's not expected to have much of a future in the rotation. If he returns in 2005, it'll be to compete for a spot in the bullpen, probably as the long reliever.
Nate Cornejo: Inc.
After a month of ineffectiveness, Cornejo was placed on the Disabled List with soreness (and later placed on the 60-day Disabled List due to a then-discovered torn labrum). Cornejo will have a long road back to competing for a spot in the rotation – he'll first need to get healthy, then return to his pre-'04 form, most notably regaining the velocity on his fastball that he had when he first debuted as a Tiger 2 seasons ago.