Ross appeared to suffer his latest concussion when he was hit by a foul tip in Baltimore on June 14.
"The results were evident in those tests. The recommendation by Dr. Collins was to basically shut down for a period of time here," said manager John Farrell. "So he's going to be away for the team. He'll return home to Tallahassee, [Fla.], until his next scheduled appointment with Dr. Collins, which is the first week of July.
"So the thing we have to really be cautious with here, it's the second time he suffered one. That will take some additional time to get over his symptoms. There's no timetable on his return. The only timetable we have is on that next appointment and where he'll be until then."
Ryan Lavarnway, who started Thursday, will be the backup catcher as long as Ross is out.