Cena filed the docs in Florida, claiming his marriage to Liz Huberdeau is "irretrievably broken." John and Liz were high school sweethearts but only married three years ago. They have no children.
Now here's the kicker -- Liz has already hired high-powered Miami attorney Raymond Rafool, the same attorney who repped Linda Hogan during her divorce ... and took Hulk to the cleaners.
But it won't be easy -- according to the docs, Liz signed a crippling pre-nup in 2009.
Liz' lawyer has already released a statement, claiming, "Although it is indeed unfortunate that John Cena decided to divorce his high school sweetheart Liz Cena; particularly, after they have come so far in their lives and in his career together, Liz will and really has no choice but to pursue all of her rights and entitlements."
The attorney adds, "Sadly, divorce is not the way Liz thought her perfect love story would end."
12:12 PM -- Liz' attorney tells us, Cena blindsided her with the divorce filing. They had been having issues -- and Cena even approached her recently with a pre-divorce financial settlement agreement -- but Liz refused to sign it, convinced the relationship would still work out.
FYI -- It's not uncommon in celeb divorces to bring up pre-divorce settlement agreements because they help simplify otherwise messy splits.