Both Sonnen, who will return to middleweight after the fight Saturday night, and Rua tipped the scale at 205 pounds. The fight will take place at TD Garden.
Sonnen is looking to snap a two-fight skid. In his most recent outing, on April 27, Sonnen was knocked out in the first round by light heavyweight champion Jon Jones. Sonnen was knocked out in the second round on July 7, 2012, by then-middleweight titleholder Anderson Silva.
Rua also is looking to get back in the win column. The former UFC light heavyweight champion was on the short end of a unanimous decision to Alexander Gustafsson in December 2012.
Overeem was in line to fight for the heavyweight title before suffering a third-round knockout loss to Antonio "Bigfoot" Silva at UFC 156 in February. Browne, who knocked out Gabriel Gonzaga on April 13, is seeking his second straight win.
All of the other fighters on the card made weight for the event.