In the past three months, Frank Johnson has been a carpenter, a television commentator, a part-time financial analyst and a full-time father. He has even done a little singing, which is appropriate, since if Johnson donned a pair of dark glasses and a fedora and posed with his injured Washington Bullets teammate Jeff Ruland, they could do a passable imitation of the Blues Brothers.

For the better part of two seasons, both men have had reason to sing a sad song. Ruland, a center/forward, has missed 81 of the team's last 146 games because of assorted injuries, the most recent a sprained left knee that has kept him out of the last seven games.

Johnson, a fifth-year guard, has suffered three breaks of the fourth metatarsal bone in his left foot since February 1985. The most recent came in a 98-93 victory over New Jersey on Dec. 28 and sidelined him for the remainder of the season.

The two men have much in common. They are close friends, they both have infant daughters and they have the same agent, Bill Pollak. They both also have heard the whispers that their NBA careers are finished because of the frequency of their injuries. Not surprisingly, both are quick to scoff at the talk.

"Why should I feel that way?" said Johnson. "It's only crossed my mind, and I quickly dismissed it because I know that's not the case. A lot of my feelings come from the doctors I've seen. They've all said this isn't a career-threatening injury -- they've got nothing to gain by saying that if it wasn't true."

Said Ruland, "Anyone who says that is just full of it. That's one of the most absurd things I've ever heard in my life."

Conventional wisdom holds that repeated injuries in the same area is a sign that the particular body part just isn't strong enough to support the physical pressure and stress that accompanies playing professional sports.

Johnson maintains that there was a specific reason for each of the breaks and that the overall problem has been alleviated by surgery: a bone graft, in which the bone that had broken each of the previous three times was removed and replaced by a piece of bone from outside his left fibula.

In the previous breaks, the foot was just placed in a cast until the break knitted, a procedure that Johnson said every doctor he consulted agreed with.

"Breaking my fifth metatarsal at Wake Forest was more severe than any of these other ones and it was all new to me," he said. "Now I'm more aware of the injury, I know what's expected of me in terms of rehabilitation."

Sources have said that Johnson's agent was displeased with the Bullets' handling of his treatment, something Pollak categorically denied. There had also been reports that Pollak wanted Ruland to sit out the rest of the season, which he also denied. "As far as Jeff is concerned, I would prefer that he heals as soon as possible, continues to play this season and leads the Bullets into the playoffs," Pollak said.

Johnson's fourth metatarsal was initially broken against the Detroit Pistons in February 1985. That summer, it cracked again, shortly after a screw was removed. After he spent the first 15 games of this season on the injured list, he came back and played well enough to start, averaging 12.6 points and 5.4 assists per game.

He was playing especially well at the time of his injury, one reason he went into a deep funk that lasted until recently, when he began his multiple-role spurt of activity and resumed attending Bullets games. "Those first 24 to 48 hours I was really down," he said. "Then I pulled out of it until it was time for the surgery. That was more depressing, having to deal with a cast and crutches again."

The timing of Johnson's latest injury couldn't have been worse. He will become a free agent after this season, presenting him with a situation that is new and a little frightening.

"I have thought a lot about that," he said. "I think I'll probably be able to get a year's contract from someone. When the time comes for me to play, teams will probably be hesitant because of my injury. A year's contract is probably all I'll be able to get."

Although not a free agent, Ruland said he wouldn't be surprised to hear his name bandied about in discussions for potential trades.

"I have no control on what they do," he said, referring to Bullets management. "If they want to trade me, that's fine, that's part of the business. I know that I'm one of the best damn players in the league, though, and I'll be back.

"Who knows, maybe this is all part of a master plan. Maybe I'll be like Bill Walton and get traded to the Celtics."

In Leon Wood, the Bullets have a good, young guard and a possible hedge against losing Gus Williams to free agency after this season or Johnson to injury or free agency. Asked to discuss the possibilities, Washington General Manager Bob Ferry said he was too concerned about the present to worry about the future.

"I love Frank Johnson. I feel terribly sorry about what's happened to him, but right now anything that would be said is just speculation, and there's no reason to do that," Ferry said. "I don't mean to sound cold, it's just that he's still in a cast and you can't see through that. That probably wouldn't be a priority until next season."

If he were forced to, Johnson said he would consider trying out with a team on a make-good basis.

"I hope that it doesn't come down to that," he said. "It's just a matter of time. When I come back, I'm coming back to play. There'll be no hesitancy on my part."