The ESPN report cites contact with 19 current or former Oregon players who estimate between 40 and 60 percent of players use marijuana, both in the past 15 years and on the current team.
University of Oregon athletic director Rob Mullens responded to the report in a statement Wednesday, saying student-athlete welfare "is of the utmost importance" to the school.
He said Oregon football players are tested for illegal drugs to the "full extent possible" under Oregon state law, which does not allow random testing.
"Similar to many college campuses wrestling with the same issue, the University of Oregon actively works to address potential use of any illegal substance through a combination of education, prevention and enforcement activities," Mullens said in a statement.
Officer: "Why are you guys smoking dope riding down the road at 118 mph?" Response: "We're just trying to get home." Officer: "How do you think (Oregon football coach Chip Kelly) would like it if I called him?"
ESPN's report included quotes from current and former Ducks players, including ex-quarterback Akili Smith, who told the magazine some players who use marijuana "go out and ball because they are relaxed."