Prior to 's , he authored one of NFL history's , ushering in the ' fleeting "."Since collapsing in a heap at the 5-yard line of FedEx Field 16 games into his career, Griffin has regre sed as much as any quarterback we've ever seen, leaving his future in question entering the 2015 season.To hear former coach Mike Shanahan tell it, injuries can't Paul George Jersey be blamed for Griffin's struggles."I don't think getting hurt ," Shanahan told WJFK-AM in Washington on Friday. "I think what you do is you rehab yourself and you get better. ... You don't have to have great running ability to run the read-option. You have to be able to know when to slide, when to throw the football away, depending on if you're running or pa sing."It must be pointed out that Shanahan has a vested interest in driving this particular narrative. From Griffin's early December knee injury versus the through the torn ACL in the playoffs of the 2013 season, for his .That said, Shanahan is unquestionably correct that Griffin's goes far beyond the injuries.By the middle of last season, Griffin . He had devolved in his footwork, failed to decipher defenses, crumpled in the face of pre sure and refused to pull the trigger on throws. His inability or unwillingne s to execute a simple baseball slide outside the pocket remains one of the league's most profound head-scratchers."Robert has a lot of ability. He's a charismatic guy Blake Griffin Jersey . He's got mobility. He's got arm strength. He's a very bright guy," Shanahan continued. "But he hasn't done things that the NFL asks you to do, and it does take some growing pains to go through that."All quarterbacks do -- you take a look at (John) Elway, you take a look at (Peyton) Manning, Steve Young -- it doesn't happen overnight, and they ran the pro offenses all the way through college. When you haven't run that type of system, it's going to take a little bit longer, and you better really work on it inside and out to get better at it or you'll just be right in the middle of the road."The middle of the road is exactly where Griffin's career stands entering a in Washington. It's fair to question if that would be the case if not for the shredded knee that robbed of his dynamic playmaking ability -- as well as his confidence.The latest Podcast and much, much more with special co-host Colleen Wolfe. Find more content on .