NFL Commissioner Paul Tagliabue, admitting his teams and scouting combines are excessively evaluating college football players, said yesterday the league will have more stringent policies in effect before the start of the season.

Tagliabue said he doesn't believe the NFL is responsible for low graduation rates among college football players, but declined to give specifics of what he will recommend, because he has yet to discuss the changes with the league's Competition Committee or 28 owners. A league meeting is scheduled for late next month, and Tagliabue said he planned to announce the revised rules in early August.

As the Knight Commission studying reforms in intercollegiate athletics began a two-day meeting here with Tagliabue as its leadoff witness, NCAA Executive Director Dick Schultz proposed that the NFL and the NBA conduct "open drafts," like Major League Baseball and the NHL, so that pro prospects can retain their college eligibility after testing the professional market if they leave school early.

At first Tagliabue declined to comment on an open draft, in which any college underclassman could be drafted without losing eligibility, saying Schultz had only "proposed it last week. I don't know if I understand it yet." Then he said, "My understanding is that you'd have to scout everybody in college and you'd also have to select people without knowing whether they have the slightest idea of playing football in the NFL."

The NBA, after antitrust suits in the early '70s, allows any underclassman to apply for "early entry." The NFL this year allowed juniors to apply for the draft for the first time. Tagliabue said the league would not allow freshmen and sophomores to enter the draft unless legally forced to, then added, "I'm sure we'll be in court within the next year or two."

And in what is scheduled to be the Knight Commission's final public sessions before formulating and presenting its recommendations next spring, commission co-chairman the Rev. Theodore Hesburgh, president emeritus of Notre Dame, indicated it may propose that all drug testing be conducted independently of the schools.

That would represent a significant policy change, according to NCAA spokesman Jim Marchiony. Currently, the NCAA conducts a comprehensive testing program for bowl games and its championships. Starting Aug. 1, the NCAA also will begin conducting in-season testing on Division I football players for steroid use.

Although the rule allows the NCAA to test randomly for all banned substances, Marchiony said the intent is to test only for steroids in Division I football. Random testing for other performance-enhancing and street drugs remains the province of each school and can lead to abuses, according to several commission members and Russ Granik, NBA deputy commissioner, who testified with Tagliabue.

"Our experience has been that the drug testing should not be run by the teams or, in your case, the individual schools," Granik said. "They tend not to know what to do with a positive test result."

Yesterday's developments came the day after the NCAA Presidents Commission, meeting in Chicago, announced it would sponsor rule changes that would reduce time demands on athletes; contain ever-spiraling operating costs with a 10 percent across-the-board reduction in scholarships, coaching staffs and recruiting; and eliminate athletic dormitories and training tables. As part of the reform package, it will allow the restoration of two of the three games chopped from basketball schedules in January.

Tagliabue's proposal to restrict the NFL's dealing with college players is the league's strongest attempt yet to placate college football coaches, who are under pressure to produce higher graduation rates and have threatened to ban from their campuses scouts and personnel men who keep their seniors out of classes their final semester.

But while Tagliabue said, "We're going to tighten our regulations on predraft scouting, . . . on minicamps {and} on flybacks for physical exams," he refused to accept total blame for the graduation rate difficulties.

Tagliabue said low graduation rates were "overwhelmingly determined by the policies and practices {of the institutions} themselves. . . . It is obvious that the high-pressure, commercialized, mass-marketed college athletic programs, involving long seasons and extraordinary athletic and other pressures that necessarily limit educational opportunities, make it inevitable that graduation rates for college athletes will be a matter of concern."