Gonzalez, 35, will compete for a spot in the bullpen. He has been throwing on his own this spring, and the Nationals aim to evaluate his progress in a bullpen session on Friday.
"He said he's ready to go," Williams said. "He's been throwing. He's throwing bullpen [sessions], things like that. I can't imagine he's faced any live hitters lately, so that may be part of the process. We'll check with him when he gets here and see where he's at."