From UFC.com

A last-minute back injury has forced welterweight contender Karo Parisyan to withdraw from his UFC 88 bout with Yoshiyuki Yoshida. Saturday’s UFC 88 card (pay-per-view 10pm ET / 7pm PT) will continue with nine bouts

Fightlinker is already howling:

You always give fighters the benefit of the doubt, but with all that talk of Karo’s serious anxiety disorder over the past few weeks, am I being callous to suggest that we’re not getting the entire story here?

If Karo isn't really injured, this could be all she wrote for one of my all-time favorite fighters.

UPDATE:  Luke has pointed out to me that speculating that the reasons for Karo pulling out of the fight without any evidence that it's NOT a back injury is irresponsible and the reason Dana hates blogs. He's right and I feel pretty guilty, especially since Karo is absolutely one of my favorite fighters.

Sherdog is reporting that they've confirmed that it IS a back injury:

Randy Couture, one of Parisyan’s primary training partners, said the fighter “put his back out” some time between Thursday evening and Friday morning and was having difficulty walking.

On the other hand, Steve Cofield is adding to the speculation that there's more to it than that, based on his recent interview with Karo, Cofield says he's "not surprised" that Karo pulled out of the fight.