10:46 AM PT -- Turns out Aaron didn't shade Donald Trump at UFC 302 Saturday night. Instead, it seems he got a little face time with the former prez -- posting a pic to IG where he's shaking his hand. So, seemingly no beef between them.

Aaron Rodgers seemed to diss Donald Trump in a very public way.

Aaron and Trump were both front and center Saturday night at UFC 302 in Newark, New Jersey.

At one point Trump, who got a thunderous ovation, walked right past Aaron, who never got out of his seat and never acknowledged the ex-Prez.

What's more ... the crowd started chanting, "F*** Joe Biden!" and Aaron is right there, covering his face.

It's highly unlikely Aaron is now a Biden supporter, but all signs point to the QB supporting 3rd party candidate RFK, Jr.

As you know, Rodgers said he was asked to be RFK's running mate but chose football instead.

It appears he's still team Bobby ... and no fan of 45.