We're told the world's most famous podcaster has a scheduling conflict leaving him unable to work the fights. Michael Bisping is taking Rogan's place for Saturday's event ... which airs on ESPN+ PPV.

Of course, the JRE host has been under fire for weeks ... starting with supposed "misinformation" spread through his immensely popular podcast. Then, last weekend a compilation video of Joe using the n-word from several years back spread across the Internet.

Rogan apologized ... but also described the situation as a "political hit job."

After the news broke, there was speculation ESPN and/or the UFC pulled Rogan.

However, our ESPN sources tell us that's not true. They say they have nothing to do with the lineup of commentators. As for the UFC, Joe is generally beloved by the company ... and we're told they did NOT pull him.

Bottom line, our sources are telling us Joe had a scheduling conflict ... and it was his decision to miss the fights.

The card's main event features a fight between Israel Adesanya and Robert Whittaker ... from the Toyota Center in Houston, TX.