The UFC has not yet officially confirmed the replacement.
Trinaldo, 40, is coming off an impressive TKO of Evan Dunham at UFC Fight Night 137 in September.
Don't blink, Francisco Trinaldo with the TKO out of nowhere! pic.twitter.com/6WkF2bs8pu
— FOX Sports: UFC (@UFCONFOX) September 23, 2018
Hernandez, 26, is currently enjoying an eight fight win streak going. He decisioned Olivier Aubin-Mercier at UFC on FOX 30 in July.
UFC 233 is scheduled for Jan. 26 at the Honda Center in Anaheim, California. Tentative bouts include:
Henry Cejudo (13-2-0) vs. T.J. Dillashaw (16-3-0)
Paul Felder (15-4-0) vs. James Vick (13-2-0)
Joanne Calderwood (12-3-0) vs. Ariane Lipski (11-3-0)
Ben Askren (18-0-0, 1NC) vs. Robbie Lawler (28-12-0, 1NC)
Yana Kunitskaya (11-4-0) vs. Marion Reneau (9-4-1)