Giovanni Ramirez, 31, remains in custody on a parole violation. His attorneys say they have handed over a list of 11 friends and relatives who maintain he was with them, not at Dodger Stadium.
And they claim they have found some independent witnesses, including business owners and workers.
"They have confirmed that they did in fact either witness or see his girlfriend with him, or the two or one of the other," said defense attorney Jose Romero. "So essentially we are searching for third-party witnesses."
Los Angeles Police Chief Charlie Beck has said he is confident that police arrested the right man.
Police have not yet identified a second attacker and a woman suspected of driving the pair from the scene. Anyone with information about the case is urged to call (877) LAPD-24-7.