Because I am confident that not only is Willis done as an effective pitcher, but every time he takes the field he will do nothing but hurt the team's chance to win.
Remember when they brought BK Kim back a couple years ago? Sometimes a guy just doesn't have it anymore, and you don't want that player taking the mound for you ever.
Billy Buckner could very well be the 5th starter next year.
Billy Buckner 4-6 with a 6.40 ERA last season age 26
Career 6-8 with a 5.74 ERA
Dontrelle Willis 1-4 with a 7.49 ERA age 27
Career 69-60 with a 4.02 ERA
It is a no brainer to give Willis a chance. If he does not get it going after 3 or 4 starts, you can then cut him. I guarantee at his worst, he give this team as much of a chance to win as Buckner, Petit, Mulvey or Augenstein. At this point the team has Haren and Scherzer penciled in. Webb should get picked up, but he may not be ready when the season start. No matter how sure you are he has nothing left, a couple of starts to see if this is true will not kill this team since at this point there is not enough quality SP's to make a run at the playoffs. Even now with Parker being a question make with health.