According to Jason Beck of MLB.com Tigers manager Jim Leyland has indicated this morning that Phil Coke starting today is a 
“My intention is to have Phil Coke in the rotation.”
Furthermore Beck says that Coke will slot in right behind Justin Verlander, Max Scherzer and Rick Porcello with Armando Galarraga some youngsters and maybe a free agent pickup competing for that final spot. One name left out of the mix is longtime starter Jeremy Bonderman which means we will probably hear more about what the team plans to do with him later today. All indications would say that Jeremy Bonderman has pitched his last game as a Tiger and will hit the free agent market this off-season.
Coke will make his first major league start of his career and was most recently a starter in Double-A Trenton in 2008.
I would rather see Coke coming out of the bullpen next season given the way he has pitched coming out of there this season and the fact that Joel Zumaya hasn’t had a full healthy season in a very long time. A lot can change during the off-season and you would have to expect that the team will make a run at a top of the line starter this off-season putting Coke back in the bullpen while having the already named players battle it out for that fifth spot.
