The rapper has recorded vocals for the track - titled 'Monster' - for the upcoming posthumous album from the King of Pop.
According to MTV, 50 Cent - real name Curtis Jackson - was "nervous" about working with the late star.
He said: "I don't usually get nervous, because I really don't care about a lot of the artists but Mike is special. He's different.
"I don't know how to explain it. When I sat down and listened to the actual song, I was excited. I said, 'This is the 2010 version of 'Thriller''."
He added that he was saddened when Jackson passed away, especially as they were not able to complete the recording together.
"I missed an opportunity to be on a record not just with a great artist, but a legend," he said. "So I wanted more, and I made adjustments to my cadence so I don't sound like I sound on music that people have previously heard from me, because I'm adjusting to the production."
The song will be included on Michael, scheduled for release on December 13.
