"Who knows where he would have been if he hadn't missed that tackle?" said the linebacker's father, Quon Clayton. "But you learn from [your] mistakes."
The primary lesson that seems to have come from Clayton's benching was to work. When Clayton arrived at Eagles minicamp, he said, he had been asked to learn the strong-side linebacker position but was planning to study the weak side as well - just in case.
Asked if he needed to add bulk to play in the NFL, he said, "If it need be for me to pick up weight, got to get to the table."
And when it came to special teams, an unglamorous job that may provide opportunities for rookies, Clayton said it just takes effort to make the difference between springing a big play or missing a block and getting "cussed out."
"I'd rather just put the effort in and get the job right the first time than sit back and let somebody yell at me," he said.
A jagged path
Practicing in the Eagles' winged helmets might not have been the exact dream Clayton had as a young man. Growing up about 80 miles east of Dallas, he spent Sundays cheering on the Aikman-Irvin-Smith Cowboys. When he went to Oklahoma, he wore No. 22 out of respect for Emmitt Smith.
His allegiances abruptly changed with a phone call from the Eagles on April 24, early on Day 3 of the NFL draft. The call woke Clayton up in his family's home.
"You know how family reacts. Everybody's in there shedding tears and slinging snot," Clayton said, a Texas drawl still detectable.
For Clayton, it was the latest big step in a journey along a jagged path. After arriving at Oklahoma as a safety, saying he spurned his home state Texas Longhorns because they wanted him to switch to linebacker, Clayton quickly got on the field.
He won the safety job, but the tackle he missed in a 2006 game against Washington allowed a 54-yard touchdown run on the first play from scrimmage. He was promptly "fired," he said. Clayton then played sparingly for the better part of two years. He thought about leaving football behind.
"You're not coming home. You come home, you're going to work," Quon Clayton remembers telling his son. He reminded him of that week one summer when Keenan joined his father at the Sulphur Springs Livestock and Dairy Auction, where the elder Clayton still works. They woke up at 5 a.m. and were on the job caring for cattle into the night - 8, 9, maybe 10 p.m., Quon Clayton said. "That kind of changed his mind on hard working."
Quon Clayton said he kept attending Oklahoma's games, even while his son sat on the bench. "I just told him, 'Keep working, keep working, keep working.' "
Clayton still got his chances to play on special teams and said he modeled himself after Lewis Baker, a teammate who "went 150 miles an hour everywhere he went."
Lining up before kicks, the two would playfully trash talk over who would get to the returner first. As they each struggled to win playing time, they saw playing on special teams as a chance to shine, Baker said.
Once, they charged so hard after a Colorado kick returner that when the runner slipped, they collided, and Baker left the game with a concussion, he said.
Eventually, at his coaches' urging, Clayton moved to strong-side linebacker and returned to Oklahoma's starting lineup. With his speed, he often covered tight ends in the pass-heavy Big Twelve.
The Eagles liked what they saw, particularly in pass coverage.
"What they did in Oklahoma translates to our defense," said general manager Howie Roseman.
Clayton, considered small but fast for his position at 6-foot-1, 229 pounds, displayed his pass-defense ability in 11-on-11 drills on Day 2 of the minicamp last month. As he faded into coverage, DeSean Jackson broke open behind him. The throw went up, but Clayton leaped and swatted the ball down with his right hand. Jackson reached out a gloved hand for a slap of congratulations.
In the locker room later, Clayton deflected praise, saying he wished he had intercepted the ball.
It was typical of a player who, so far, has been engaging and humble with the media and highly self-critical. When a reporter brought up Clayton's speedy 40-yard dash - his time of 4.66 seconds at the NFL combine ranked among the best for linebackers - the rookie said he should have been faster. When someone else asked him about making big plays, Clayton credited his coaches with putting him in the right place.
"That sounds just like him," said Brad Turner, Clayton's high school coach. "He wasn't a flamboyant guy. He wasn't a showboater."
Clayton will head into training camp - and a week-long minicamp starting Wednesday - at a position where the Eagles struggled to find an answer all last year and where they are thin on experience. The top strong-side linebacker is Moise Fokou, a second-year man with five career starts.
Quon Clayton and his family hope to see Keenan on the field when the Eagles travel to Dallas on Dec. 12. Once taunted by his Texas friends for sending a son to an out-of-state rival for college, they're already giving him heat for abandoning the Cowboys for the Eagles. Quon Clayton, though, said he's proud to be a new Birds fan.
"People talk about how wild they are," he said. "I think I'll fit right it in."
Contact staff writer Jonathan Tamari at 609-989-9016 or firstname.lastname@example.org.