Of course, Costa was sitting Octagon-side when Izzy knocked out Robert Whittaker last weekend at UFC 243 in Australia ... and the two talked trash to each other after the fight.

So, when we spoke with White this week he told us the two fighters are on a collision course ... and if Israel emerges victorious, then we can start talking about Izzy vs. Jon Jones.

"The next fight is Paulo Costa. That's the fight to make next and if a Jon Jones fight is possible down the line, I like it!"

Israel and Jones traded shots on TMZ over the past few months -- Israel said he's a G.O.A.T. killer and Jon replied, "I'll make you call me daddy!"

There's more ... we also spoke with White about Justin Gaethje -- who's been trying to draw out Conor McGregor for the past 7 months.

Dana tells TMZ Sports ... Conor is currently laser-focused on a rematch with Khabib Nurmagomedov, which leaves Justin in wait-and-see mode.

"I think what needs to happen now is Khabib is gonna fight Tony Ferguson and we'll see how that plays out and where that leaves Justin Gaethje."