Robert Griffin III has been cleared to play in the Washington Redskins' regular-season opener, but coach Mike Shanahan said Thursday night that doesn't necessarily mean the star quarterback will face the Philadelphia Eagles.

Dr. James Andrews cleared Griffin after examining the QB's surgically repaired right knee before Washington's 30-12 preseason win Thursday night against Tampa Bay.

Griffin confirmed he had been cleared to play in a tweet after the game:

Operation Patience....Complete. Cleared. To God Be The Glory http://t.co/GxYMw8Cs57 — Robert Griffin III (@RGIII) August 30, 2013

But speaking after the game, Shanahan declined to say whether Griffin would start the Sept. 9 opener against Philadelphia (7 p.m. ET on ESPN).

"I did talk to Dr. Andrews," the coach said. "He's going to approve Robert can play. There are a couple concerns that he has. I'll talk to Robert over the weekend and I'll let [the media] know on Monday where we're at."

Griffin tore multiple ligaments in his right knee late in the Redskins' playoff game against Seattle last season.

It appeared to be a foregone conclusion earlier in the week that Griffin would start the opener as long as Andrews cleared him. Both Shanahan and his son, offensive coordinator Kyle Shanahan, talked about how well Griffin looked in practice and how his reps increased. Kyle Shanahan even said that, in his eyes, Griffin looked to be 100 percent.

And Griffin told ESPN 980 radio Tuesday morning that he was 100 percent recovered from the Jan. 9 surgery. He said he could have run a time of 4.3 seconds in the 40-yard dash if he had been at the NFL scouting combine.

What Andrews saw that troubled him is uncertain. He has watched Griffin up close a couple of times since training camp started, and there had been no concerns expressed publicly. Andrews did tell Mike Shanahan before camp began that Griffin should not play in the preseason, which he hasn't.

Griffin didn't start taking reps in 11-on-11 work until the final week of training camp two weeks ago, and that was against the scout team. He started taking reps against the starting defense last week.