Mary Tillman has a message for the National Football League: Help me find out what happened to my son.

Inspired to serve his country after 9/11, Pat Tillman gave up a lucrative career with the Arizona Cardinals to join the Army in May 2002. As a Ranger, he participated in Operation Iraqi Freedom, then fought in Afghanistan, where he was killed in April 2004.

Tillman’s death was mourned coast to coast, and the public and his family were told by the Pentagon that he died a “warrior’s death” charging up a hill, urging on his fellow Rangers. His funeral was nationally televised, and Arizona Sen. John McCain, now the presumptive Republican presidential nominee, was among those delivering eulogies.

President Bush took time from his 2004 reelection campaign to address Cardinal fans on a Jumbotron during an emotional halftime ceremony in which the Arizona franchise retired Tillman’s jersey number.

Yet the circumstances of his death turned out to be an obscene hoax. Tillman was, in fact, killed by friendly fire.

Now, after six investigations and two congressional hearings, there remain many unanswered questions about Tillman’s death and the Army’s initial investigation of it. His family has challenged the Bush administration, the Pentagon and the media to uncover the truth.

To keep the public pressure on, Mary Tillman has written a book, “Boots on the Ground at Dusk: My Tribute to Pat Tillman.” In a recent interview with me, she was highly critical of the actions of the NFL because she believes it continues to bathe in the glory of her son’s patriotic sacrifice while doing little to help the Tillman family find out how Pat died.

“I think the [NFL] has not gone out of its way to help,” she told me. The league has “exploited Pat, just like the military. ... [It has] a beautiful statue to him at the Cardinals’ stadium. I don’t know if that’s more for us or the [NFL]. I feel like it’s more for the league.”

War and patriotism, of course, have long been associated with the culture of football. Quarterbacks are routinely referred to as “field generals” who throw “bullets” and “bombs.” Some coaches walk the sidelines with the gravity of a Gen. George Patton. Military airplanes overfly many stadiums before games begin. Military recruiters often set up booths at football facilities.

The NFL has seized on Pat Tillman as another way to connect with the red, white and blue sports fan. Earlier this year, former Commissioner Paul Tagliabue brought together the NFL and the United Service Organizations to build the Pat Tillman USO Center at Bagram Air Base in Afghanistan. And the league just opened an exhibit dedicated to Tillman at its Pro Football Hall of Fame in Canton, Ohio.

Now the Tillmans want the NFL to help them speed up the latest congressional hearing into Pat Tillman’s death.

The league certainly seems to have the clout to get things moving. Owners of professional football teams are some of the wealthiest and best-connected people in the United States. In the 2004 election cycle, NFL and other sports teams owners gave $14.6 million to Democrats and Republicans, as well as to independent political committees. San Diego Chargers owner Alex Spanos gave a $4-million donation to the Progress for America Voter Fund, which backed Bush.

As Kent Cooper of PoliticalMoneyLine, a nonpartisan research group, told USA Today, “I don’t think the public is generally aware that [pro team owners] give these big donations.”

Last year, the House Committee on Oversight and Government Reform, which is overseeing the inquiry, asked the administration for all documents related to Tillman’s death and cover-up. The administration gave the committee what it described as “mostly press clippings” because of “executive branch confidentiality interests.” The committee’s chairman, Rep. Henry A. Waxman (D-Beverly Hills), and its ranking minority member, Rep. Thomas M. Davis III (R-Va.), protested that the documents shed virtually “no light on these matters.”

Meanwhile, 20 veterans who saw combat in Iraq and Afghanistan took the extraordinary step last August of writing a letter to NFL Commissioner Roger Goodell, asking his help in securing the release of the requested documents.

Unfortunately, the league has not responded to Mary Tillman or the veterans.

“If this [a death of family member or friend under unclear circumstances] had happened to any one of us,” said Mary Tillman, “Pat would have gone through a wall to find out the truth. So, it’s the least I can do and the least any one of us can do [to find out how he died.]”

And that should include the National Football League and Goodell.

Dave Zirin is the author of “Welcome to the Terrordome: The Pain, Politics and Promise of Sports.”