John Mackey's suffering is over, but even in death he keeps giving to the game he loved.
Mackey, the Hall of Fame tight end who played nine seasons for the Baltimore Colts, died Wednesday of frontal temporal dementia
But soon researchers at the Boston University School of Medicine will study his brain to see if there's a link between repeated concussions in football and chronic traumatic encephalopathy (CTE), the perfect storm of head injuries that leaves ex-players reeling from depression, dementia, suicidal thoughts and God knows what else.
This much is certain: Few athletes ever have the impact on their sport — both on and off the field — that No. 88 had.
For openers, he revolutionized tight end, once the Ugly Betty position in pro football.
Before Mackey, tight ends were big, slow guys given one simple assignment by their coaches: go block someone and get out of the way. If the quarterback threw a pass their way, it was usually out of desperation.
But Mackey was different. He was big, strong and fast. And when he caught the ball, he could turn a routine 5-yard pass into an electrifying big play that broke the heart of the other team.
"He [was] the model tight end that is required today in the NFL," said Tom Matte, the two-time Pro Bowl running back who played for the Colts from 1961-1972.
"Oh, my God, after he caught the ball, he was like a fullback running downhill!" said Bruce Laird, the Colts safety who played with Mackey in 1972 and heads up Fourth & Goal, the advocacy group for retired players. "This guy was 250 pounds, delivered blows and wouldn't go down."
If you have to be a little mean and a little edgy to play football, Mackey qualified on that count, too.
He delighted in running over would-be tacklers, even when he knew he was fast enough to avoid the contact. And he wasn't the type to run out of bounds, unless there was someone there he could steamroll, too.
Matte remembers a Colts game in 1966 against the Detroit Lions in which Mackey caught a short pass from quarterback Gary Cuozzo and leveled every defender on his way to a 64-yard touchdown run.
"It was the most fantastic run I've ever seen in football," he said. "There were eight different guys that hit him and they all bounced off him."
Mackey's fierce play on the field and his classy, elegant way off it so endeared him to his teammates that they reacted in typical jock fashion: they made him the target of every prank in the book.
"I remember someone had shot a rabbit," Matte recalled. "We looped a rope over the pipes at old Memorial Stadium and hung the rabbit over John's locker. Someone kept lowering it and lowering as he sat there.
"Finally it came down over John's head. He looked up and let out this blood-curdling scream."
In 1970, Mackey became the first president of the NFL Players Association after the merger of the NFL and AFL.
"He was a smart guy and an articulate man, and he was able to bridge the gap between the two [leagues]," Laird said.
Mackey quickly strong-armed NFL owners with a three-day strike that resulted in $11 million in pensions and benefits for the players. Two years later, the NFLPA won a landmark antitrust suit that gave the players free agency, and the league would never be the same.
"He saw where the NFL was heading," Matte said. "If you look at the history of the league, he was involved in so many important [issues]."
By the early 2000's, though, it was becoming obvious that something was wrong with Mackey.
His old Colts teammates reacted with increasing alarm to his odd behavior, his forgetfulness, blank stares, startling flashes of temper over minor incidents.
At the funeral Mass for Colts Hall of Fame quarterback John Unitas, Mackey left his seat at one point and stood in the middle of the aisle for several minutes, seemingly disoriented.
"It was very, very hard to watch," Matte said. "To see a guy with the intelligence he had, the stature in the game, to just crumble before your eyes …"
Overwhelmed with the expenses of caring for her husband's dementia, Sylvia Mackey appealed to then-NFL commissioner Paul Tagliabue for help. And not long after that, the league and the players union instituted the "88 Plan," which provides up to $88,000 for nursing and day care for ex-players with symptoms of head injuries.
But Mackey's own condition continued to worsen. At a celebrity bash at the Sports Legends Museum two years ago, Sylvia Mackey spent much of the night trying to calm her husband, whose paranoia grew worse and worse as the evening wore on.
"He was confused and agitated," said Mike Gibbons, the museum's executive director. "Sylvia knew it was the last time we were going to see him."
Now he's gone, but what a legacy John Mackey leaves behind.
And as the NFL owners and players continue meeting to end one of the most ridiculous labor disputes in the history of organized sports, both sides would do well to pause and remember all that John Mackey did for the game.
He was one its giants.