In a stunning revelation, Rey Mysterio reveals in his new book Rey Mysterio: Behind the Mask that he entered a drug rehab clinic in 2008 due to some issues he was having with pain medication.

Apparently, it was related to on-going problems he endured with his biceps last year.

As you may remember, Mysterio suffered a biceps injury in February of 2008 and underwent three surgeries within one month to try and correct the problem.

Read more about it in the book below...

	WWE: Rey Mysterio - The Life of a Masked Man List Price: $29.93 Sale Price: $17.99