...a concussion when he was hit in the head by a pitch from San Francisco Giants' Matt Cain on Aug. 16. (AP Photo/David Zalubowski

...the plate by teammate Brad Hawpe (11) after hitting a home run off San Francisco Giants' Matt Cain during the fourth inning of a baseball game Wednesday, Sept. 16, 2009, in San Francisco

SAN FRANCISCO - AUGUST 30: Matt Cain #18 of the San Francisco Giants pitches against the Colorado Rockies at AT&T Park on...

...L) SAN FRANCISCO - AUGUST 30: Matt Cain #18 of the San Francisco Giants pitches against the Colorado Rockies at AT&T Park on...

If the Giants make the playoffs, they'll be relying massively on Tim Lincecum and Matt Cain -- their offense is historically bad among contenders

...T Park in San Francisco, California. (Photo by Jed Jacobsohn/Getty Images) SAN FRANCISCO - AUGUST 9: Matt Cain #18 of the San Francisco Giants throws a pitch against the Cincinnati Reds at AT&T...

...is helped off the field after being hit by a pitch thrown by San Francisco Giants' Matt Cain during the fourth inning of a baseball game, Saturday, Aug. 15, 2009, in New York. (AP...

July 24, 2009; Denver, CO, USA; San Francisco Giants starting pitcher Matt Cain (18) delivers a pitch in the second inning against the Colorado Rockies at Coors Field. Mandatory...

DENVER - MAY 07: Starting pitcher Matt Cain #18 of the San Francisco Giants delivers against the Colorado Rockies during MLB action at Coors...

...Busch Stadium in St. Louis, Missouri. (Photo by Dilip Vishwanat/Getty Images) SAN FRANCISCO - JUNE 14: Matt Cain #18 of the San Francisco Giants pitches against the Oakland Athletics during the game at AT...

14 June 2009: Giants #18 Matt Cain pitches a complete game during the San Francisco Giants 7-1 win over the Oakland Athletics...

San Francisco Giants' Matt Cain pitches against the New York Mets in a baseball game in San Francisco, Sunday, May 17...

SAN FRANCISCO - APRIL 9: Matt Cain #18 of the San Francisco Giants pitches against the Milwaukee Brewers during the game at AT...

San Francisco Giants v Colorado Rockies DENVER - MAY 07: Starting pitcher Matt Cain #18 of the San Francisco Giants delivers against the Colorado Rockies during MLB action at Coors...

April 21, 2009; San Francisco, CA, USA; San Francisco Giants pitcher Matt Cain (18) pitches against the San Diego Padres during the first inning at AT&T Park in...