"We're trying to be thorough and do our due diligence in a situation where he hasn't responded in the first couple days," head athletic trainer Barry Weinberg said on Saturday. "He hasn't gotten better, so we'll try to investigate all possibilities.
Gonzalez was held out of game action for a fifth straight day on Saturday while the Cardinals explore the situation.
"It's tough," said Gonzalez, who is trying to make the team as a non-roster invitee. "It's hard for me."
Gonzalez last played in a game on Monday, when he went 2-for-4 against the Braves in Orlando. That was his first time playing the outfield this spring, after appearing exclusively as a designated hitter earlier in Grapefruit League play.
He complained of symptoms in the area of the injury on Wednesday, causing him to be scratched from the Cardinals' lineup against the Marlins. The club originally hoped that rest and treatment would ease Gonzalez's discomfort, but he remains unavailable.
"I do not think he was better this morning," manager Tony La Russa said on Saturday afternoon. "He's been resting and getting treated, so that's not a good sign."
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.