A year ago, Len Elmore was a seldom-used backup center who was wondering whether there was any life left in his aching knees or his NBA career.

With his confidence badly shaken by the nonshooting role he was asked to play in Milwaukee, the former University of Maryland star quietly was making plans to go into television production full time.

The Bucks had all-star Bob Lanier as their center, with defensive standout Harvey Catchings and young, muscular Pat Cummings to fill in. In the seven-game Eastern Conference semifinal against Philadelphia, Elmore played 12 minutes and took one shot.

"I knew I didn't have any future in Milwaukee," Elmore says. "I was just wondering if I had any future at all."

Since that time, Elmore has made one of the most remarkable reversals in the league, and he qualifies as comeback player of the year. Many are considering Seattle's Gus Williams for the honor, but the only thing he came back from was a long contract dispute that kept him idle last season.

For the past 51 games, Elmore, 30, has been the starting center for the New Jersey Nets. It's no coincidence that the young team has risen from last place to third during that period. Tonight they will bring a 35-34 record to Capital Centre (WTOP-1500 at 8:05) for an important game with the Bullets.

"I don't know where we'd be without Lenny," said Coach Larry Brown. "I never anticipated he'd play this well. He's been around the league a long time, and I was just hoping he had something left. He was fading himself out of the NBA and suddenly turned himself around."

Elmore hardly was at the top of the Nets' priority list in training camp. The plan then was to go with Mike Gminski, despite his disappointing rookie year. The former Duke star had a back infection during the summer, however, and still wasn't strong enough to play during the exhibition season.

Brown's first choice as an alternate was Sam Lacey, a 12-year veteran from Kansas City. Negotiations were slow, however, so to bridge the gap, the Nets obtained Elmore from Milwaukee for a second-round draft choice.

Elmore was delighted. It was a chance to come back East after all those undistinguished years in the Midwest with Indiana, Kansas City and the Bucks. It was a final chance to prove that he belonged in professional basketball.

"I know a lot of people thought I couldn't play anymore," Elmore said recently. "I hadn't been a starter for a long time, I wasn't getting a lot of playing time, therefore my scoring was down. I still believed in myself, though. I still thought that if I ever was given a chance, I could still play. If I didn't, I would have gotten out of this a long time ago."

The last season he was a regular, with Indiana in the American Basketball Association in 1975-76, Elmore averaged 14.6 points and 10.8 rebounds. The following year he went out with a knee injury after only six games. By the time he returned, Dan Roundfield, then James Edwards had taken his job. He was traded to Kansas City and sat behind Lacey for a year before becoming a free agent.

Milwaukee signed Elmore because Coach Don Nelson wanted an experienced, intelligent center in case Lanier's ailing knees gave out. However, with all the talented scorers on the team, Elmore was not encouraged to shoot.

"Everybody had a role in Milwaukee and mine was defense," Elmore recalled. "I know we had a lot of good shooters, but when you go into a game and know you're not supposed to look for your shot, well, it gets discouraging. After awhile I was losing confidence and becoming hesitant."

This season Elmore already has played more minutes than he has in any year in the last five and made more field goals than the past two seasons combined. He has started 57 games and is averaging 8.7 points and 5.1 rebounds. His shooting percentage also is very respectable--.467 compared to his lifetime mark of .390.

"I love playing for Larry Brown," he said. "There was no role, no restrictions when I came here. He just told me to go out and play basketball. If I had an open shot, I was to take it.

"At first, I was hesitating, just out of habit, I guess. Let's face it, teams were giving me the 15-footer because I didn't have a reputation for making them. I started taking them, and the more I shot, the more sure I was of myself. Now I look for the jumper, and I think it helps us because other teams have to play me honest."

Against Dallas, Elmore scored a career-high 25 points and against Golden State he had a personal high of nine field goals. Although Ray Williams (20 points a game) and forwards Buck Williams, Albert King and Mike O'Koren do most of the scoring, Elmore plays an important role from his spot at the top of the key.

"Lenny always was fundamentally sound," said Bullets Coach Gene Shue. "I really liked him in college. His knee problems have slowed him down, but he's hurt us in two games this season. He benefits a lot by playing alongside a strong forward like Buck."

Elmore sank seven of 10 shots, plus nine of 10 free throws, for 23 points in the Nets' 114-108 victory Jan. 5 at Capital Centre. He came back March 3 to score 18 points in the Nets' 130-124 double overtime victory.

"It's so much easier to play well when you know you're going to start every night and you're going to play a lot of minutes," Elmore said. "I haven't had this luxury in a long time, and I'm really enjoying it."

Jim Chones had his sore left foot X-rayed yesterday and there was no sign of a fracture. He still is limping, however, and probably won't play tonight . . . The Nets will be without Otis Birdsong, who reinjured his sore right knee . . . The Nets have a 2-1 edge over the Bullets, winning twice here. The season series is important because it serves as the first tie breaker if the teams are tied at the end of the year.