Originally published on ProWrestlingSheet.

WWE legend Blackjack Mulligan has been hospitalized ... so says the wrestler himself  -- and according to reports, it's why Bray Wyatt and Bo Dallas were noticeably absent from RAW.

The 73 year-old wrestler posted an update on Facebook Monday which reads, "I'm sorry to say I'm in the hospital trying to pass blood clots.will keep you posted."

Hours later, Dallas and Wyatt were missing from Monday Night RAW ... and PWInsider reports they flew to Tampa to be with their grandpa while he's in the hospital.

For those unaware, real life brothers Bray Wyatt and Bo Dallas are also the grandsons of 2006 WWE Hall of Fame inductee Blackjack Mulligan -- part of the famous tag team "The Blackjacks."

Stay tuned to Pro Wrestling Sheet for any further updates on his condition.