Robert Griffin III’s knee buckles Sunday night (John McDonnell/The Washington Post)

Redskins quarterback Robert Griffin III and team owner Daniel Snyder arrived at the Andrews Institute for Orthopaedics and Sports Medicine in Gulf Breeze, Fla. Tuesday for further evaluation of Griffin’s injured right knee by surgeon James Andrews.

As of 4 p.m., the examination was continuing, according to a person with knowledge of the matter. It wasn’t clear how long the visit would last or which tests were being conducted, the person said.

The quarterback and the team expected to gain greater clarity about the damage to Griffin’s right knee, which he re-injured in Sunday night’s 24-14 playoff loss to the Seattle Seahawks. An MRI conducted Sunday night, several hours after Griffin left the game, indicated that the rookie had suffered possible partial tears to his anterior cruciate and lateral collateral ligaments.

There were conflicting opinions among Redskins’ doctors about whether the results showed old injuries or fresh ones, Coach Mike Shanahan said Monday. Griffin tore his ACL as a sophomore at Baylor in 2009, and suffered a Grade 1 sprain to his right LCL four weeks ago.

The team sent Griffin for an extensive examination by Andrews, a top orthopedic surgeon.  One person with knowledge of the situation said it was possible that Griffin would have exploratory surgery on the knee.

The Redskins had no immediate comment about the results of Griffin’s examination. The team has said it would make a formal announcement when there is a definitive diagnosis about Griffin’s injury. It was not clear whether that would come Tuesday.

DeMaurice Smith, executive director of the NFL Players Association, said in a televised interview Tuesday that the union is gathering information about the Redskins’ handling of Griffin’s injury.

“I did ask our medical director to reach out to Dr. Andrews and to reach out to the team,” Smith said during an appearance on ESPN. “It’s a question whether or not we’ll actually do a formal investigation pursuant to Article 50 of the [collective bargaining agreement]. But there was enough of an inconsistency or a question about whether the process of evaluating the player occurred, whether he was cleared to play, not cleared to play.”

Smith said the union also is looking into the condition of the playing surface at FedEx Field during Sunday’s game.

“Today I did ask our general counsel to reach back and let’s try to figure out what were all of the certifications for the fields for last week’s games,” Smith said. “I’d be interested in seeing what that certification is, not only for FedEx but at every game in every stadium. That 100-by-50-yard surface is our players’ workplace and we have a question about whether or not teams are employing the best efforts to keep the workplace as safe as possible.”

The Redskins did not immediately respond to a request for comment on those issues.