"I didn't feel the trade was fair for the small-market Grizzlies," said Stern. "I mean, looking back, they really got fleeced. So I am voiding the deal for basketball reasons."
The commissioner's decision attaches a huge question mark to the last four NBA seasons, in which Gasol and the Lakers made three NBA Finals and won two.
"I guess that means the Lakers lose those two championship," said Stern. "Or not. I don't know. Maybe we could have a computer simulate those seasons or ask some kid to do it on NBA 2K. There are obviously a lot of questions and I don't have the answers. When you start meddling in things, this is what happens, okay? Just let me meddle."
It's the second Lakers trade in as many days that Stern has nixed, yesterday voiding a three-team deal that would have sent Gasol and Lamar Odom out of Los Angeles in return for Hornets point guard Chris Paul.
"Now people will stop harping on me about the Lakers-Paul trade finally," said Stern. "Because now that the Lakers never even had Pau Gasol, of course the Chris Paul trade couldn't have happened. So get off my ass. I'm great at my job."
Stern will now reportedly also send Kobe Bryant back to the Charlotte Hornets in exchange for Vlade Divac.
New Lakers head coach Mike Brown will likely open camp with a team featuring Divac, Crittenton, Brown, McKie and Marc Gasol.
"I really hate David Stern right now," said Brown. "I had a chance to coach Kobe and CP3 and now I have the worst team ever."