Legendary boxing trainer Freddie Roach is currently working with Georges St-Pierre -- and he may have just dropped a huge bombshell about GSP's future fighting plans.

Maybe. 

Roach was leaving Craig's in L.A. when we asked what he thought of Conor McGregor's boxing skills. Spoiler -- he thinks Conor sucks. 

But that's when he dropped this gem -- "GSP's gonna kick his ass anyway."

Here's the thing ... GSP is currently training for his UFC 217 fight against Michael Bisping. If he wins, could a Conor fight be next? That's what Freddy seems to be getting at. 

FYI, GSP is fighting Bisping at 185 pounds -- but he's previously said he can cut to 155. 

Conor is the champ at 155 -- but he fought (and beat) Nate Diaz at 170. 

Let's face it -- this would be a HUGE fight for Conor and the UFC. Maybe even bigger than Conor vs. Nate III. 

So, does Roach know something we don't? Or is it just wishful thinking?

We reached out to the UFC and were told, "GSP is coming back after 4 years off. Conor is looking to defend his title. There is zero talk about GSP vs. Conor."