The Washington Redskins will open the 2019 NFL Season in Philadelphia.
"It's not good for Colt obviously but like I said, what's most important for Colt is to get that (leg) to where he can fire off of it, push off of it," Gruden said. "It's his right leg, so he's not getting enough fire off of it push off of it and until he feels like he's 100 percent doing that, I'm not going to put him back there."
"I have faith in the trainers and the doctors," Gruden said Sunday. "That's all you can do and then the players have to buy in and do what they have to do to get ready."
The Skins head coach added there is no "rhyme or reason" as to why some injuries take longer for some players to recover from.
"Look around the league, some ankle sprains last a week, some last six weeks, some last eight weeks and then it could be a different degree. Same thing with AC joints, hamstrings, I've seen those things get better in a week, some last about eight weeks," he said. "So, it's up to the players to do the work, the doctors to give them the direction, and the trainers to work them.
"And I feel like we have a good enough staff to do that. We just have had different types of injuries that some have lasted longer than others. We've had a lot of guys that have injuries that have come back quickly but that don't get talked about so there is some good also."