A. J. Johnson's 1990 season was supposed to have ended on an operating table in Arlington Hospital last June.

After undergoing reconstructive surgery on his right knee, the Redskins' second-year cornerback was expected to make it back for the end of the regular season only if rehabilitation went flawlessly. And apparently from the looks of things, it did. Johnson rejoined the team on Thursday and yesterday completed his second day of practice.

Coach Joe Gibbs, whose most pressing concern is Monday night's road game against the Philadelphia Eagles, called Johnson's recovery "the best of the ones that I've seen, particularly for a skill guy. . . . He had an absolutely perfect surgery and rehabilitation. He hasn't had one glitch in there. That's hard to do with that kind of injury. We're thrilled about it. The doctors have done a great job and the rehab guys have done a great job."

Johnson, a 1989 sixth-round pick from Southwest Texas State, last year became the first Redskins rookie to lead the team in interceptions, tying Alvin Walton and Brian Davis with four. He began the season as the nickel back, before taking over at left cornerback for the final eight games. He also displayed promising versatility by averaging 21 yards on 24 kickoff returns, finishing seventh in the NFC.

But he injured the anterior cruciate ligament in his knee during mini-camp, and after team orthopedic surgeon Charles Jackson performed the operation, Johnson was told he would be inactive for at least six months.

"It depended on who I was talking to," Johnson said. "One {doctor} said a year, another said six months . . . I was just going to go with it until it felt better. I was going to let my body tell me when it was ready."

By the time his body gave him the go-ahead, he had already overcome the mental aspect of the rehabilitation. "I was never afraid of {putting pressure on the knee}," he said. "I've never been afraid to play on it."

As for his stunning recovery, Johnson shrugs it off. "I just went along with the program," he said. "I just stayed with what I was told to do. Hey, things happen. It ain't no big thing. I just have to come back."

Johnson said it probably will be a few weeks before he is ready to return to the active roster. "What I'm doing out here is just getting used to working out and getting in shape," he said.

"I think he's kind of rough out there right now; he hasn't had a camp or anything," Gibbs said. "But it's good to get him back out there and we're gradually going to get him back in."

Redskins Notes: Assuming Johnson does eventually return to the active roster, he'll be the fourth Johnson to play for the team this season. The others are tight end Jimmie, defensive tackle Tim and cornerback Sidney . . .

The Redskins have not won on Monday night since Oct. 19, 1987, against Dallas, 13-7. They since have dropped five straight.