Lopez has signed a two-year contract with Melbourne and coach Ernie Merrick said: "The timing of me going over to Costa Rica between AFC Champions League games was when Saprissa were in the finals, so I saw him play and he was quite outstanding.
"The focus of my trip was to watch him play in the finals and to talk him into coming to Australia and we were successful on both accounts."
Lopez replaces ex-Chelsea winger Joe Keenan, who had his contract mutually terminated overnight, as Victory's fourth foreign player alongside Hernandez, Scotsman Grant Brebner and Brazilian Ney Fabiano.
"We were always aiming to add another creative, holding midfielder and the job description really meant that we wanted someone with good experience, who can cope with the rigours of that position and the stress of playing for a club that needs to perform well on a regular basis in front of good crowds," Merrick added.
"He also had to be a very attacking minded player and a great distributor of the ball, and I was lucky enough to come across a Costa Rican teammate of Carlos, who's a regular in the national team.
"Five years ago he joined Saprissa, Costa Rica's top club, and that time Saprissa paid the highest ever domestic transfer fee for a player.
"He's got a terrific record. He captained Saprissa, played in World Cup qualifying matches, played in the Olympic team with Carlos and played in the FIFA Club World Cup, where Saprissa finished third behind Liverpool and Sao Paulo.
"He's just turned 27, he's an experienced player and he'll bring a lot of maturity into the midfield.
"He's another fantastic addition with outstanding credentials, and together with our key recruits Michael Thwaite, Ney Fabiano, Billy Celeski and Tom Pondeljak, we're putting together a very strong and exciting side for 2008/09."