It had been a year since Donald Brown last played football, and he was looking forward to this trip with his new Maryland teammates to Vanderbilt. He had transferred from Oklahoma a year ago, gotten his grades in shape, and even took a screen pass 70 yards for a touchdown in a scrimmage on just his fourth day of practice.

As he pressed his dress suit, Brown figured he didn't have a problem in the world. But when he got to the locker room to meet teammates for the trip south, he also got some bad news. There had been a mix-up. A confusing but innocent mix-up had canceled both his trip to Nashville and his season.

What follows is the story of how a running back with extraordinary physical gifts has been tackled by confusing rules and regulations that no one seemed to understand until it was too late.

When Brown transferred from Oklahoma before the 1982 season because a freshman named Marcus Dupree was coming to take his position, he enrolled in University College, a school on the University of Maryland's College Park campus that generally is thought of as a part of the university, but has separate curriculum and degree requirements.

When a student-athlete transfers, NCAA rules stipulate he must establish a year of residency at the new school before he can play. Brown had a 1.99 grade point average at Oklahoma, which allowed him to remain eligible for football. However, that was .01 below the mark required to transfer to the University of Maryland-College Park, or any other NCAA Division I school. But Brown thought he could establish the year of residency by enrolling in night classes at University College, which is a branch of the state university system.

He worked as a bouncer to pay his tuition and commuted four times a week from his home in Annapolis. The Maryland football staff said last winter it would not monitor Brown, but talk about scholarship possibilities only if he improved his grades. The staff also was under the impression that if he did fulfill his academic obligations at University College, he would be eligible to play this year.

Brown's grades were good enough this summer--two Bs and a C--for him to be accepted into the University of Maryland this fall. His transcript was sent from the university registrar's office to the Atlantic Coast Conference. But because of a computer malfunction at Maryland, his transcript failed to note that he had played at Oklahoma. When the omission was discovered, the registrar's office informed the ACC. The registrar's office contacted the ACC the day before the opening game at Vanderbilt. And after going over the NCAA rule book one more time, the conference determined that Brown, who had practiced all week, was not eligible.

Barbara Riggs, who works in the registrar's office, reviewed the transcript that Friday and found the omission. According to university officials, all the transcripts of first-year players and transfers are reviewed before the first game as a matter of course. Riggs yesterday declined to comment.

In this case, the NCAA interpretation is that Brown actually transferred twice, once from Oklahoma to University College, and then from University College to the University of Maryland. The second transfer would mean that he had to sit out another year, this year.

ACC Commissioner Bob James said the conference first ruled Brown eligible because it didn't know he had attended Oklahoma. And, said James, who played football at Maryland and was a dean there, even though Maryland students take courses at University College, the two institutions have separate curriculums, separate administrations and separate graduations. Therefore, attending University College did not meet the NCAA's criteria for residency.

"It's strange, and a lot of people aren't going to understand how this young man won't be eligible even after he went to a school on the same campus as the University of Maryland," James said. "But he would have had to transfer directly to the University of Maryland, not University College."

Brown, who returned a punt 70 yards for a touchdown when he was a freshman at Oklahoma, was to return kickoffs for the Terrapins at Vanderbilt. If he had played, James said, Maryland would have had to offer Vanderbilt a forfeit. Meanwhile, Brown practices every day, but on game days is idle for the second straight year. His 4.48 speed in the 40-yard dash is idle. The talent that attracted Oklahoma Coach Barry Switzer to visit three times in Brown's senior year at Annapolis High School is idle. This week, Brown said he would like to appeal to the NCAA to regain his eligibility.

"The coaches asked me if I wanted to go to Vanderbilt," Brown said, "but I just went home to Annapolis and cried. I just got on the bed, started praying and crying. But now, there's nothing apparently that can be done. I don't understand it."

Brown, 6 feet, 195 pounds, is nicknamed "Turkey" because he was born on Thanksgiving Day. He was such an outstanding player in high school that Oklahoma wrote and asked him to send film of his first three games. "They said Coach Switzer couldn't just come across the country to look at somebody," Brown said.

Switzer saw the films of Brown rushing for more than 100 yards each game and came across country. "You could imagine how I felt at 17 years old having Barry Switzer come to see me," Brown said.

"That film was pretty darned impressive," Switzer said by phone from Norman, Okla. "He's some player."

Brown estimates he played in six games at Oklahoma in 1981, some as a third-string tailback, some as kick returner. But then Oklahoma recruited Dupree, considered the premier running back in the country.

"Coach Switzer came to me in the spring (of 1982) and told me when Marcus got to town, I'd be switched to wide receiver or defensive back," Brown said. "I'd never played defense in my life and you know how much Oklahoma throws the ball. Who wants to leave Oklahoma? But I told him I'd rather go back home and try to find a school where I could still be a running back. So I contacted Maryland, which also had recruited me, and asked if they had any space for me," Brown said. Maryland said it certainly could use him.

"I'm still 19 years old and, if I can get that year back, I'd be right on schedule," Brown said. "I'd love to appeal; I dream about it every night. I know I can play. Before that scrimmage I hadn't played in a year, and I still ran 70 yards. I was rusty. Suppose I had a week or two to get my moves down. Coach (Bobby) Ross has been great to me. I'll be patient, do anything he asks me to do. But I want to play."

James said he will meet soon with Brown and explain as best he can. "I feel for the young man," he said.

So Brown, who now is eligible for two more years, comes to practice every day and, surprisingly, always seems to be in a pleasant mood. But last Saturday, when Maryland was being beaten by West Virginia and could have used Donald Brown, he stood behind the bleachers looking up at the scoreboard, knowing there was nothing he could do.