At 5-foot-7 and 195 pounds, Abdulqaadir simply may not have been quite big enough for the N.F.L. But he and others suggest that Washington State and the N.F.L. rebuffed him for an unprecedented reason: the alleged terrorist activities of his father, Mujahid Abdulqaadir Menepta. “The way this country works, that probably was the reason he didn’t get his opportunity,” Jacobs says.

An African American convert to Sunni Islam and an associate of Zacarias Moussaoui—whom authorities once fingered as the so-called 20th hijacker—Menepta gained notoriety as one of the first U. S. citizens detained as a material witness after the September 11 attacks. According to his arrest warrant, he was investigated for destruction of aircraft, bombing conspiracy, and seditious conspiracy to levy war against the United States, among other charges.

A congressional report on 9/11 described Menepta as a member of the radical Muslim Brotherhood and vice president of overseas operations and recruiting for Fatah, the Palestinian political party. Menepta denies both affiliations. His name also surfaced in federal investigations into the bombing of the World Trade Center in 1993 and the Oklahoma City Federal Building in 1995. He pleaded guilty in December 2001 to a weapons violation but was never charged with terrorism and was released from prison in November 2002.

When Abdulqaadir, then a Coffeyville sophomore, visited his father in detention, Menepta warned that major colleges and the N.F.L. would blackball him. Abdulqaadir, who had lived apart from Menepta since 10th grade, was skeptical—but no longer. “I did everything I was supposed to do, and I didn’t get the proper outcome,” he says.

It’s an axiom among football agents that no player ever believes that the N.F.L. cut him because he wasn’t good enough. That’s why Boston sports agent Brad Blank reserves a special place in his heart for Gordie Lockbaum. In Blank’s 27 years of representing would-be pros, only Lockbaum—who finished third in 1987 in the voting for the Heisman Trophy, awarded to college football’s best player—admitted lacking N.F.L. ability. “There’s a lot of guys who have marginal N.F.L. talent,” Blank says. “It doesn’t always work out. I get hundreds of calls a year from kids who say, ‘I’m being discriminated against.'"

Still, Blank and other insiders have never heard a story like Muhammad Abdulqaadir’s: an N.F.L. prospect with a parent deemed a national security threat. The league’s flag-waving, patriotic public image invites the question of whether the N.F.L. or individual teams may have quietly decided that the son of an alleged terrorist would be bad for business.

After 9/11, the N.F.L. wrapped itself in resurgent nationalism. The 2002 ­Super Bowl featured N.F.L. stars reading the Declaration of Independence, Paul McCartney singing “Freedom,” and a Budweiser ad with Clydesdale horses bowing to the Statue of Liberty. Clutching the trophy, Robert Kraft, owner of the victorious New England Patriots, proclaimed, “We’re all patriots.” Military flyovers and the unfurling of enormous American flags have become pregame staples. No N.F.L. player has emulated baseball’s Carlos Delgado, who refused to stand for “God Bless America” in 2004, or basketball’s Mahmoud Abdul-Rauf, suspended in 1996 for remaining seated during the national anthem.

Because Abdulqaadir wasn’t rated as a top draft pick, his father’s notoriety “probably would have disqualified him,” says Tom Marino, a former N.F.L. scout. “A guy with a terrorist father—it would scare me. The directive could have come from the top: Don’t get involved with this guy.” The league, he adds, “is very, very image conscious.”

Although Abdulqaadir’s situation is unique, it does reflect broader tensions over the treatment of Muslims in the workplace. In the fiscal year ending September 30, 2007, 607 Muslims filed charges of religious discrimination with the Equal Employment Opportunity Commission, up from 284 in 2000.