The 25-year old has been on trial with the team since February and was offered a contract, which he is now awaiting approval for.
Quakes head coach Frank Yallop said Robles would bring a lot of versatility to his playing roster and was very complimentary of his workrate in training.
"He's a good all around player that can play wide right, and can play in the middle," said Yallop. "He has good feet and a good soccer mind. Also, he's pleased to be here in San Jose and he's settled in very nicely with the team. We expect some very good things from Javier.
"We are not asking him to play defensive, and yet he still gets his tackles in, and his work rate in," said Yallop. "He doesn't appear to be the biggest of players, but he is quick and clean; hopefully he'll settle in well in MLS."