Howard Sidney Slusher was born on June 11, 1937, in Jersey City, N.J., and grew up within the Williamsburg section of Brooklyn. His father, Sam, was a salesman; his mother, Dorothy, was a homemaker.
He played football and baseball and ran track in highschool; majored in physical education at Brooklyn College, where he received a bachelor’s degree in 1959; and earned a Ph.D. in physical education from the Ohio State University in 1962.
He taught the psychology of sport on the University of Maryland after which on the University of Southern California until 1972, when he received a law degree there. In his book “Man, Sport and Existence: A Critical Evaluation,” published in 1967, he wrote that athletes have the power to find a reality beyond themselves.
“The pole-vaulter defies gravity, the sprinter explodes through resistance and the swimmer dares massive forces,” he wrote.
The distinguished baseball agent Scott Boras, who read Mr. Slusher’s book when he was in law school, said in a phone interview that Mr. Slusher “learned law and loved the psychology of sport,” adding, “To do the perfect in your client, you may have to grasp the psychology of who you’re negotiating with so you possibly can arrive at a good solution.”
Mr. Slusher first encountered Mr. Knight, the Nike chairman emeritus, while negotiating a shoe endorsement contract in 1975 for Paul Westphal, then a guard with the Boston Celtics. After extracting an additional $5,000 from Mr. Knight after it seemed that the talks had ended with a three-year, $75,000 deal, Mr. Knight told an associate to rent “that son of a bitch,” in response to the book “Just Do It: The Nike Spirit within the Corporate World” (1994), by Donald Katz.