"RIP To The Legendary O.J. Simpson," the former Rams All-Pro said on Thursday. "Your favorite RB favorite RB ... Appreciate you Uncle O/Juice you'll be missed."

Gurley didn't just acknowledge Simpson's success on the field ... he also made note of his recent endeavors -- including his usual appearances as an analyst on rappers Cam'Ron and Ma$e's "It Is What It Is" podcast.

"Thanks for the past year being on It Is What It Is!!," Gurley added. "Heisman, #1 pick, NFL MVP & the first ever 2000 yard rusher let alone to do it in 14games the list goes on & on!🙏🏾🕊️."

Gurley isn't alone in mourning Simpson's death ... as we previously reported, numerous pros took to social media to share positive messages on the former Bills star -- and retired receiver Torrey Smith called on news outlets to show more respect by avoiding using images from his infamous trial.

Some social media users have taken issue with their support ... after all, despite his acquittal in the criminal case, he was found liable for the deaths of Nicole Brown Simpson and Ron Goldman in the civil case.

Caitlyn Jenner -- who used to be tight with Simpson -- sided with those upset over all the love for O.J. on Wednesday ... saying simply, "Good riddance."