Too slow to be a great safety, too small for an NFL linebacker, he got by on toughness, effort and brains. Then he walked away from a multimillion-dollar NFL career to join the Army Rangers and serve his country.
This week, he paid with his life. Tillman was killed in an ambush Thursday night in Afghanistan. He was 27.
"Pat represents all that is good with this country, our society and ultimately the human condition in general," said Seattle Seahawks general manager Bob Ferguson, who was General Manager of the Arizona Cardinals when Tillman was drafted.
"In today's world of instant gratification and selfishness, here is a man that was defined by words like loyalty, honor, passion, courage, strength and nobility. He is a modern-day hero."
U.S. military spokesman Lt. Col. Matthew Beevers said Saturday that Tillman was killed in a firefight on a road near Sperah, about 25 miles southwest of a U.S. base at Khost.
After coming under fire, Tillman's patrol got out of their vehicles and gave chase, moving toward the spot of the ambush. Beevers said the fighting was "sustained" and lasted 15-20 minutes. He was killed by enemy fire.
"That's real tough country," said CBS News Military Consultant Perry Smith. "It's very mountainous country, the government of Pakistan has never really been in control, there are a lot of tribal elements there. There are a lot of elements that support radical groups like al Qaeda. That's where there's been the greatest amount of combat activity over the last few months."
, who wore a black ribbon with Tillman's name on it and a Cardinals helmet pin with the No. 40 attached.
"Pat Tillman personified the best values of America and of the National Football League," Tagliabue said Saturday, flanked by five Marines. "Like other men and women protecting our freedom around the globe, he made the ultimate sacrifice and gave his life for his country."
A memorial was set up outside the Cardinals' headquarters, with his No. 40 jersey in a glass frame, and a giant poster with Tillman on one knee, in uniform, on the Cardinals' sideline.
People brought flowers, teddy bears and balloons. One man in uniform and kilt showed up to play "Amazing Grace" and "America the Beautiful" on a bagpipe.
"A lot of times in football, analogies of war are thrown around freely," former Cardinals teammate Pete Kendall said. "On a day like this, you see how hollow those ring."
The Cardinals said they will retire Tillman's No. 40 and name the plaza surrounding the new stadium under construction in suburban Glendale the "Pat Tillman Freedom Plaza."
Arizona State will retire his No. 42 jersey during a Nov. 13 game and place his name on the honor ring at Sun Devil Stadium. The university and the Cardinals also are collaborating on a scholarship fund in Tillman's name.
In college, Tillman was a long-haired wild man on the field, an all-Pac-10 linebacker always going full-speed. Bone-jarring hits were his trademark. He helped lead the Sun Devils to the 1996 Rose Bowl and a year later was the Pac-10 defensive player of the year.
But he excelled off the field, as well.
He graduated summa cum laude in three-and-a-half years. He earned a marketing degree with a 3.84 grade-point average.
The Cardinals took Tillman in the seventh round of the 1998 draft, the 226th player chosen.
At first, he made his mark on special teams but played his way to starting safety.
In practice, coaches often had to make Tillman slow down so he wouldn't hurt anybody in drills that weren't supposed to be full-speed. Before the 2000 season, he ran a marathon to see what it would be like. Before the 2001 season, he gave the triathlon a try.
In May of 2002 - eight months after Sept. 11 - Tillman walked into the office of then-coach Dave McGinnis, pulled up a chair and said "Mac, we have to talk."
Tillman and his brother, Kevin - a baseball player in the Cleveland Indians minor league system - were going to join the Army Rangers, soldiers sent where the fighting is toughest.
He never said a word about his decision publicly.
"It was his wish that this not be something that would draw a lot of attention," McGinnis said. "He truly felt committed and felt a sense of honor and duty at this point in his life that this is what he wanted to do."
Some 110 U.S. soldiers have died — 39 of them in combat — during Operation Enduring Freedom, which began in Afghanistan in late 2001.
Tillman's agent, Frank Bauer, has called him a deep and clear thinker who has never valued material things.
In 2001, Tillman turned down a $9 million, five-year offer sheet from the Super Bowl champion St. Louis Rams out of loyalty to the Cardinals, and by joining the Army, he passed on millions more from the team.
Tillman turned aside interview requests after joining the Army. In December, during a trip home, he made a surprise visit to his Cardinal teammates.
"For all the respect and love that all of us have for Pat Tillman and his brother and Marie, for what they did and the sacrifices they made ... believe me, if you have a chance to sit down and talk with them, that respect and that love and admiration increase tenfold," McGinnis said at the time.
It was not immediately clear when he went to Afghanistan.