I think it’s pretty clear that Matt Cain is the bassist, Brian Wilson is the drummer and Tim Lincecum is the heartthrob singer/guitarist. I can’t come up with a fitting name, though, so your suggestions are welcome.
Photo from the Montreal Gazette, via Jonah Keri.
Tedquarters 
Couldn’t come up with anything strictly relevant but thought I’d post some anyway:
Timmy and the Machine
Blistered Finger
Moneyballs
Giant Threat
Caine and Abel
um..I’ll give up now!
Meat Socket.
I have no idea why, thats just what popped into my head.
The FreakBeard
The Mission District
The Cove
Big Bay
Slide Piece
The Fe Fi Fo Fums. Wow, that was terrible. Sorry.
The Freak Machine (feat. Curly Cain)
Keith Pitchers
Fastball II
F*ck the Bucket
I think Fastball II is the winner.
That big guy on the right is Matt Cain? He’s gonna be played by John C Reilly in the biopic. Who plays the others?
Great call on JCR for Cain. I’d say the kid from Dazed n Confused is consensus for Lincecum and I’m going Ryan Golsin(g?) for Wilson.
Vitamin K. And for the movie, I’ll go with Colin Farrell and Joseph Gordon-Levitt.