Band co-founder Armando Lichtenberger Jr. says Oscar De La Rosa and his driver were knocked unconscious by a man they didn't recognize in the attack early Monday. Lichtenberger says De La Rosa is resting at his Houston home Tuesday.
No arrests have been made. Houston police are looking for a man who became violent after being thrown out of the bar.
Lichtenberger says De La Rosa has facial cuts, eye damage and he lost two teeth.
He says La Mafia is considering whether to cancel any performances.
The band, which formed in 1980 in Houston, won a Grammy in 2006 for the album, "Nuevamente."