Cowboy Cerrone to Conor McGregor, 'Sign the Damn Deal, Let's Get This Done'

Donald "Cowboy" Cerrone says Conor McGregor has NOT signed the official UFC contract to fight on Jan. 18 ... and now he's putting the pressure on Conor to get the deal done.

Of course, 31-year-old Conor announced his UFC comeback last week during a media event in Russia ... saying he'll fight on Jan. 18 but wouldn't reveal his opponent.

36-year-old Cowboy tells us both his team and Conor's team have been in contact with the UFC, but they're still trying to "figure it out."

"I think it's gonna happen this time," Cowboy tells TMZ Sports ... "I really do. Conor's really serious about making a comeback."

Cowboy says he knows Conor vs. Cowboy is the fight "everyone wants to see" and says he's "pumped" at the idea of sharing the Octagon with the Irish superstar.

"It's gonna be a fun fight! He's a great fighter. I'm not taking anything away from him by any means, he's got a lot of punching power ... and it should be a good time!"

In fact, Cowboy had a message for McGregor -- "Sign the damn deal man, let's get this done!"

Oh, we also asked if Cowboy has tried Conor's Proper 12 whiskey ... and ya gotta hear his review!