Griffin III suffered tears to his right anterior cruciate ligament (ACL) and lateral collateral ligament (LCL) during the Redskins' playoff game against the Seahawks in January.
In his first public comments since the end of the season, Allen echoed those sentiments at the groundbreaking ceremony for the Richmond training center, saying he was pleased with Griffin III's progress.
"I think he has such a great commitment and positive attitude," Allen said. "He’s remained positive and he knows that he’s going to be bigger and better than ever."
With regards to the rumors that Griffin III could be ready to play Week 1 of the regular season, Allen said he would respect the rehabilitation process and defer to the team's doctors.
"We’re going to let the doctors quote him where they are," he said. "I know Dr. Andrews was hopeful after the surgery and we’ll see how it progresses.
"This will be an ongoing thing throughout the offseason."
Allen also fielded questions about tight end Fred Davis, who is scheduled for free agency after playing in 2012 under the team's franchise tag.
Davis appeared in only seven games this season, registering 24 receptions, 325 yards and no touchdowns.
His season was cut short by a torn Achilles in the Week 7 game against the Giants, a devastating injury that could affect his availability for 2013.
Allen said it was too early to gauge his long-term status, but was hopeful for a full recovery.
"He's progressing well," he said of Davis. "That’s a very serious injury and we won’t know a lot until later in the Spring.
"But he’s working very hard and we expect that he’ll have a full recovery."