Guard Charles Johnson, who thought his pro basketball career might be over three weeks ago, signed a multipar contract yesterday with the Bullets.

Johnson joined Washington last Tuesday after agreeing to a 10-day contract, which was to expire before this week's All-Star break.

But Bullet General Manager Bob Ferry said he was so impressed with Johnson's performances in his three games with the team that he decided to offer him a permanent contract. Johnson had been cut by the Golden State Warriors Jan. 4 after five years with the club.

Johnson's signing comes in the wake of growing feeling within the Bullet camp that guard Phil Chenier may not recover from his back problems enough to help the team until the playoffs. There is also some fear now that surgery may be required to correct the problem, a degenerative disc in the lower back.

Bullet sources, however, deny that Johnson was signed because of concern about Chenier. They say that his play since joining the club, plus the fact other teams were starting to show interest in him, prompted the team's action.

Chenier has been in Sibley Hospital since Jan. 20 for back treatments. The earliest he could return, according to the club, is the middle of February.

If Chenier returns by the end of February, the Bullets must either cut someone, most likely rookie Phil Walker, or they will have to put Mitch Kupchak on the injured list. Kupchak is out until mid-March with torn ligaments in his thumb.

Johnson scored 28 points in his three Bullet appearances and has impressed Motta with his defense, even though he has had to guard taller opponents. He has nine points in the fourth quarter of Sunday's 119-112 victory over the Lakers.