Four-time world champion Brian Viloria returns to the ring for the first time since losing the WBO and WBA flyweight titles last April when he faces Juan Herrera on Saturday at the Texas Station Casino in Las Vegas.

The fight is considered a tune-up bout for the 33-year-old Viloria (32-4, 19 KOs), who is expected to be on the May 31 Top Rank card in China against a big-name opponent.

Viloria had his six-fight win streak end last April in a split-decision loss to Juan Francisco Estrada.

Herrera is 9-7 with four knockouts. The fight will be shown on UniMas television.

Elsewhere in mixed martial arts:

» Maui’s Kendall Grove fights in the opening bout of "Bellator: 114" on Friday night at the Hard Rock Hotel and Casino in Las Vegas.

Grove (19-13) has won two straight fights heading into his bout against Brett Cooper (19-9) as part of a middleweight tournament.

The fight will be shown on SpikeTV.

» Brothers Bryson and Brenson Hansen will fight in preliminary bouts at "World Series of Fighting: 9" on Saturday at the Hard Rock Hotel and Casino in Las Vegas.

Bryson Hansen (6-1) faces Sean Cantor (1-0) in a 135-pound bout, while Brenson Hansen (5-2) takes on Boostayre Nefarios (2-1) in a 145-pound fight.

Both fights can be seen via the promotion’s Web site at wsof.com.