Duke, 27, wore the Bryan shirt during a recent get-together with Modafferi and fellow UFC star Shayna Baszler.
In Modafferi's photo, Duke wears a Bryan shirt and Baszler is seen in a "Haters Wanted" signature t-shirt from The Miz.
Adding to the overall cuteness of the pic, Modafferi sports a custom Jessamyn Duke t-shirt.
Duke appears to be the latest celeb to be fascinated by the "Yes Movement," one of the fastest-growing trends in the world.
Every time Bryan walks out to the WWE ring, he gets the crowd to chant "Yes! Yes! Yes!"
Funny enough, the slogan originated from UFC star Diego Sanchez and his famous UFC 95 entrance.
During that walkout, Sanchez put a mean look on his face and started chanting "Yes! Yes! Yes!" Bryan saw that fight and he was so inspired by it that he adopted it as his own signature slogan.
"People like to do it because it's fun and it's interactive," Bryan said of the 'Yes' chant. "When you're part of an arena, a whole arena with thousands upon thousands of people doing it, it's very, very surreal.
"I don't know what is going on in my world that this happened," he added. "Now these basketball teams are doing something that I made popular. How this all happened is surreal."
"The Gun" is well-known for her love of pro wrestling and the WWE, as she's an official member of Ronda Rousey's Four Horsewomen group and a regular attendee at the star judoka's WWE viewing parties.
Who knows? We might even see Duke attempt to get a "Yes" chant going during the walkout for her UFC 172 fight against Bethe Correia.
"Throughout WWE's history our Superstars and their catchphrases have often become part of the pop-culture lexicon, and Daniel Bryan's 'Yes!' chant is the latest example of this phenomenon," said Stephanie McMahon, WWE's Chief Brand Officer. "WWE is all about having fun, bringing people together and making them smile, and the Yes! Movement accomplishes all of this at WWE events and beyond."