Shamrock, 49, confirmed the news from his official Twitter page.
"@50cent - it's been a pleasure working with you and your team, you are by far one of the classiest gents I have ever worked with. God bless," Shamrock tweeted on Jan. 9.
Shamrock explained that that he's now working for a company that does private security for high-end clients, including several famous musicians, but that he's not officially 50 Cent's personal protector.
He was simply assigned to protect him at Las Vegas' CES Convention last week.
Shamrock's MMA career
"The World's Most Dangerous Man" was trying to get a fight last summer at Ultimate Cage Fighting Championships in England, but the bout fell through when the promotion was unable to come to a contractual agreement with him.
With that said, it's probably better off that Shamrock ended up taking the security job.
MMA is not a young man's game, and Shamrock continued to compete inside the cage long after his prime had passed.
Shamrock, who finished his MMA career with a 28-15-2 record, continued to fight into his mid-40s, and the results were not very good by the end of his run.
He ended up losing seven of his final nine fights, so it was clear Shamrock had reached the end of the line when it came to active MMA competition.
As the old adage goes, "When one door closes, another opens."
And that is exactly what happened with Shamrock as far as his MMA career went. It's nice to see him landing on his fight in another career.