Duffy (12-1), who defeated "The Notorious" by submission in 38 seconds in 2010, returned to competition in 2014 after almost three years away from MMA, scoring back-to-back finishes under the Cage Warriors banner in Europe.
After going 1-2 in his first run in the UFC, Rocha (11-4) earned another shot in the promotion after winning four in a row, but tapped to Jake Matthews in his return at UFC Fight Night 55. His only win inside the Octagon came in a second-round rear-naked choke over Cody McKenzie in 2011.
Headlined by Anthony Pettis vs. Rafael dos Anjos for the lightweight championship, UFC 185 takes place at the American Airlines Center in Dallas. In the co-main event, recently crowned strawweight champion Carla Esparza puts her title on the line against Joanna Jędrzejczyk.