The Showtime event will take place at the Palms Casino Resort, Challengers' homebase starting with Strikeforce Challengers 17 on July 22.
Gurgel (14-7), who made his name with the UFC from 2006-2008, will be returning to action under the Zuffa umbrella with this fifth appearance for Strikeforce. Gurgel is 2-2 with Strikeforce, holding wins over Conor Heun and Billy Vaughan and losses to Billy Evangelista and K.J. Noons. Often criticized for his preference to strike instead of taking advantage of his Brazilian jiu-jistu black belt background, Noons answered the critics in March with a 44-second submission against Vaughan. The guillotine choke victory was Gurgel's first submission in over six years.
Duarte (9-2), seven years younger than Gurgel, was a contestant on The Ultimate Fighter 8, but was not picked up by the UFC at the conclusion of the show. Duarte joined Strikeforce this past April, defeating Saad Awad via armbar submission in the second round.
On the Strikeforce schedule, Strikeforce Challengers 18 follows the July 30 Fedor vs. Henderson card and precedes a not-yet-announced card targeted for Sept. 10.