The Celtic Warrior return to WWE Saturday night and fans took notice of the incredible shape he's gotten himself into.

Sheamus recalled the exact moment he suffered ... took one big bump in the last one before I went away in my last match. I think it was Edge's last match. I just took an awkward fall, and that ...

Sheamus has already completed 15 years with WWE and has always stayed in shape, revered for his hard-hitting in-ring style.