The story of Robert Griffin III’s rehabilitation from January knee surgery has trickled out in occasional tweets and texts, in vague proclamations from the Washington Redskins and Griffin’s doctor of the quarterback’s ahead-of-schedule progress, and in sporadic interviews. With the midpoint between Griffin’s Jan. 9 surgery and the Redskins’ Sept. 9 regular season opener at FedEx Field having passed earlier this month, however, the condition of Griffin’s body and mind remains unknown, at least to those outside his inner circle. “Physically and mentally, he’s doing as well as he always has, because of his attitude,” Griffin’s mother, Jacqueline, said in a telephone interview last week. “He’s doing great. He knows that his surgery was a success and he’s ahead of schedule, and he’s looking forward to the upcoming season. Nothing has changed, really. We’ve always had a positive outlook, no matter what happens.” As the Redskins prepare for the first full-squad workouts of 2013, which begin Monday at Redskins Park in Ashburn, the mystery surrounding Griffin’s condition may soon be over. Members of the media will be permitted to view parts of those workouts Thursday, and while Griffin is not expected to be involved in offensive drills, he will perform his daily workout routine with team trainers and other rehabbing teammates. That same day, Griffin is expected to address as a whole the media who cover the Redskins for the first time since Jan. 6, when he was injured during the fourth quarter of the team’s 24-14 loss to Seattle in the first round of the NFC playoffs. It was later revealed that he tore the lateral collateral ligament in his right knee, and three days later in Gulf Breeze, Fla., surgeons — overseen by James Andrews, a Redskins team orthopedist — also repaired a torn meniscus and revised the reconstruction of the anterior cruciate ligament that was first surgically repaired in 2009. The injury, which occurred when Griffin remained in the Seahawks game despite visual evidence that his injured knee was deteriorating, set off a firestorm of criticism and debate over whether Redskins Coach Mike Shanahan, or perhaps Griffin himself, should have removed the quarterback from the game sooner. In the more than four months since, Griffin’s media availability has been limited to a handful of cursory group interviews, a sit-down interview with the in-house “Redskins Nation” that primarily rehashed the 2012 season and an ESPN The Magazine cover story. In March, Griffin sent a cryptic text message to an ESPN host in which he said, “I know where my responsibility is within the dilemma that led to me having surgery to repair my knee and all parties involved know their responsibilities as well.” Efforts to engage Griffin in an elaboration of that statement have been unsuccessful.