The Twins will likely be without pitcher Boof Bonser for
the entire 2009 season after doctors discovered partial tears in the labrum and
rotator cuff in his right shoulder during arthroscopic surgery on Wednesday.

Two previous MRIs done on Bonser’s shoulder had revealed
no structural damage. But the tears were discovered and repaired during the arthroscopic
scope performed by Rays orthopedist Dr. Koko Eaton.

Bonser is expected to miss six to eight months recovering
from the surgery.

The pitcher first began experiencing shoulder discomfort
at the end of last season. An MRI performed at that time revealed no structural
damage, and Bonser was ordered to rest the shoulder and begin a rehabilitation
program.

But the rehab didn’t help. Bonser tried to throw in early
January and felt the same discomfort. The right-hander received a cortisone
shot from Dr. Eaton just a few days before he reported for Spring Training, The
shot had little effect on the problem, and Bonser has not really thrown since
workouts began last Monday.

With Bonser out of the mix for the Twins bullpen,
right-handers Philip Humber, who is out of options and Jason Jones, a Rule 5
pick, are now the favorites to win the final spot if the Twins keep seven
relievers. R.A. Dickey, a knuckleballer, and left-hander Sean Henn are also
among those expected to compete for the job. 

There is a chance that the Twins could break camp with an
11-man pitching staff, meaning just six relievers will make the Opening Day
roster, but so far that appears to be a long shot.