Washington Redskins quarterback Joe Theismann joined his team's seemingly endless injury list this week, but will play Monday night at RFK Stadium against the Atlanta Falcons with his jammed left thumb taped or possibly in a small brace.

Coach Joe Gibbs said yesterday at Redskin Park that Theismann was hurt "on an exchange" during practice Friday. However, there were other indications that the right-handed Theismann was injured in an off-field mishap.

Theismann ran the first team offense as usual yesterday, but with his thumb taped. After practice, his hand was wrapped in ice. Asked how his hand was, Theismann said, "I'm fine." He declined to elaborate.

Gibbs said the injury will present no problem in taking snaps from center Rick Donnalley.

This week, the Redskins listed 15 players on their weekly injury report to the league. Thirteen were listed as "probable" for Monday's game, while tight end Don Warren (thigh bruise) and special teams captain Otis Wonsley (sprained knee and ankle) were termed "questionable," a 50 percent chance they will not play.

Yesterday, fullback John Riggins (sore back), guard Russ Grimm (thigh bruise), Wonsley and Warren did not practice. In addition, safety Tony Peters, who has been struggling for several weeks with an abdominal strain, limited his practice and linebacker Mel Kaufman again received treatment for a thigh bruise.

Gibbs said he expects everyone, including Wonsley and Warren, to play against the Falcons.

Perhaps the most remarkable aspect of the mounting injuries is the way the Redskins have managed to fill holes. Wide receiver Calvin Muhammad was acquired from the Los Angeles Raiders in midseason; Donnalley, obtained from the Pittsburgh Steelers, is considered a capable replacement for center Jeff Bostic and, last week, in the 37-13 loss to the Giants, running back Jeff Moore caught a career high nine passes for 75 yards and a touchdown.

Three weeks ago, Moore expected to be working for the Mississippi school system as a drug counselor. When he was cut by the San Francisco 49ers after their final preseason game, the five-year veteran figured his career was over.

But the Redskins called and, so far, Moore, who is 6 feet and 196 pounds, has impressed his new employers as a good receiver in long yardage and third down situations.

"I was no longer wondering where I would be playing next; I was beginning to wonder 'if,' " Moore said. "The Falcons will have to be looking for me now."