The proposed modified draft of college players agreed to this week by the National Football League Management Council and the players' union is expected to extend 10 rounds, 12 at the most. The Washington Post learned yesterday.

It was also learned that a modified compensation clause, or "Rozelle Rule," likely will involve draft choices only. No exchange of veteran players is expected to ccur.

The compensation formular will be determined by the free-agent player's most recent salary (for example, if a player with a $50,000 salary plays out his option, his former team may be compensated with a No. 2 draft, choice. If a $100,000 player is involved, a No. 1 choice could be the compensation.)

The new system would not require any decision from commissioner Pete Rozelle, who had ruled on such cases before the courts said that practice was illegal.

In recent years, the NFL draft went 17 rounds. But the courts have ruled the drafting of college players illegal, so a compromise was reached similar to what was accepted last year by the National Basketball Association and its players' union.

A 10-round draft would help put a price tag on players below the superstar level for purposes of bargaining. Thus, if Heisman Trophy winner Tony Dorsett was drafted by Tampa Bay (0-14) and, after hard bargaining could not reach an agreement, there would be alternatives for him.

Dorsett could sign at the minimum league salary - $15,000 in the expired labor contract - for one season plus an option year and after that time become a free agent and shop among all 28 teams.

Or he could sit out the season and be subject to the draft again the next year. Or he could sign for a long-term graduated salary based on the average salary in the league.

The so-called Rozelle Rule has been suspended since being struck down in a Minneapolis court.

Because of court decisions, if a veteran played out the option year of his contract he would, on May 1, become a free agent, able to deal with any team in the league.

Last year, the Redskins signed tight end Jean Fugett, running back Calvin Hill and fullback John Riggins as free agents without having to compensate their former employers.

Before 1976, if a new team signed a free agent, it had to compensate the original empployer. When the two clubs could not agree on comensation - be it draft choices and/or veteran players - the commissioner was empowered to determine compensation.

The players contended this inhibited free movement because of the new club's "fear of the unknown," or the amount of compensation it would have to pay.

Now, it is expected that when a player declares he is playing out his option, every other club will know before negotiating with him how much compensation must be paid to the original employer.

There is a precedent to this proposed system. After his 1972 season with the Chicago Bears, wide receiver Dick Gordon played out his option. There were six or seven teams interested in sigining Gordon but those teams considered the Bears' demands on compensation excessive.

When Gordon threatened in 1972 to join John Mackey's antitrust suit against the compensation clause, Rozelle took then unprecedented action by notifying the cluds that whichever signed Gordon would have to give up a No. 1 draft choice for 1974.

Gordon was signed by the Los Angeles Rams in October of 1972, went to Green Bay in November of 1973, to the New England Patriots in early 1974 and finished out that season at San Diego.

The NFL Management Council and the union had previously favored such predetermined compensation. The union specified it preferred that no veteran players be part of compensation.