With 135-pound champion Dominick Cruz sidelined with a knee injury, Faber (26-5) will look to secure UFC gold for the first time in his career against replacement opponent Barao (28-1). Both weighed in at the 135-pound limit.
In addition to promising a compelling fight at UFC 149, Faber has promised to defend the belt if necessary in Cruz's absence.
"I'm just super excited to put on a good show," Faber said. "Barao is tough, but not as tough as I am."
All 22 fighters set to compete on the card came in on weight.
It's been speculated Lombard would earn a shot at middleweight champion Anderson Silva with an impressive showing Saturday.