The Redskins, who already possessed two of the oldest defensive tackles in the league, added another yesterday when they picked 14-year veteran Curly Culp off the waiver list in an apparent attempt to strengthen their sagging defensive line. Culp, at his request, had been waived Thursday by the Houston Oilers.

To make room for Culp, who is 34 and a five-time Pro Bowl participant, the Redskins put wide receiver John McDaniel, the club's seventh-leading receiver, on injured reserve. Coach Jack Pardee said McDaniel twisted his ankle yesterday in practice "and we didn't know how long it would keep him out, so we decided to put him on the list." McDaniel now will have to stay out for at least four games before he can be activated.

The acquisition of Culp, who has played nose guard at Houston since 1974 but was benched this season, came as a surprise because the Redskins, struggling with a 3-7 record, appeared ready to begin going with young players.

But Pardee, who said this might be the first of a number of moves by the Redskins, maintained that Culp "has been a good player recently enough to be worth a gamble to see if he can help us. He's the type guy who can line up and play. He's been a tremendous pass rusher and he has great strength.

"Age certainly was a factor we had to consider. But he has never had any injury situations at all and guys his age who haven't and who still want to play can have some good years left. Only time will tell that."

Pardee said he hoped Culp would be in uniform for the Eagle game Sunday. The coach said he would not hesitate to use him in passing situations. "No matter what system you are in," Pardee said, "the keys are still the same. You line up and go after the passer."

Culp had been removed by Houston the last few years during obvious passing situations. And this season, he was replaced in the starting lineup after four games by former free agent Ken Kennard. He has played in 84 straight games and started since coming to the Oilers in 1974 in a trade with Kansas City. Ironically, the Chiefs picked up John Matuszak, who had a brief stay with Washington, in exchange for Culp, along with first- and third-round draft choices.

Culp, who is 6 feet 1 and 265 pounds, is considered by many to have been the prototype middle guard for teams that made the switch from the 4-3 to the 3-4 defense during the mid-1970s. He is extremely strong and was noted for his ability to clog up the middle on runs.

But Culp never has liked the middle guard position. He has maintained he was a "sacrifical lamb who had to give up my body for the sake of the linebackers."

Now he will join Diron Talbert, 36, Paul Smith, 36, Perry Brooks, 25, and Dave Butz, 30, as a Redskin defensive tackle. Butz and Smith are the current starters, although both Talbert and Brooks have been first-stringers this season.

The Redskins have generated an inconsistent pass rush all season and clubs have been able to run on the front four. The defense has had particular problems the last two weeks when it surrendered 74 points and almost 800 total yards.

Culp asked Houston Coach Bum Phillips to release him on Thursday.

"I needed a change in scenery," Culp said last night on the phone from Houston. "I wanted an opportunity to contribute to a team more than I was to Houston. I gave the decision a lot of thought. It wasn't something you decide overnight, especially when you leave a team like Houston.

"Now I feel like a young stallion again. I'm ready to play. I always have had desire, and now this is an added dimension. I feel really super about the whole thing. I didn't want to wait until the end of the season to do this, I felt it was better for me to do it now and get situated with another team."

Culp seemed enthused about returning to tackle, although he said the Redskins had not told him what position he would play.

"I'm familiar with tackle. I played it with Houston some and when I was with Kansas City.I guess I was considered to be the No. 1 person at nose guard but yes, returning to tackle again will be a challenge."

Culp said last year was one of his best seasons and that this season, considering his reduced playing time, "I probably played close to my ability. I'm ready to play Sunday. I've got a lot of ability left in me. I know I still can play in this league."

Since being replaced by Kennard, Culp has been shuffled in and out of the lineup as the Oilers employed six defensive linemen. He has 19 tackles and seven assists for the season, but no sacks.

Pardee said the Redskins were the only club to claim Culp off waivers.

"I'm sure some of the teams who are in the playoff run didn't want to change their squads around. And if teams weren't in the playoff run, his age might have been a deterrent. But he's been a good player. We will see if he can strengthen our team. If he can, it's what we are looking for."

Asked if the Redskins would be making more moves, Pardee said, "We'll continue to try to experiment, to see if we can upgrade our team with players who can play now as well as later on."

Culp, a second-round draft choice by Denver in 1968, played in the Pro Bowl in 1971 and in 1975-1978. He was named the NFL's outstanding defensive player by one wire service in 1975.Last year, he had four forced fumbles, three sacks, 54 tackles and 24 assists.

McDaniel, a seven-year man, had caught 14 passes this season but only one in the past five weeks. He led the Redskins in receiving yards in 1978 after coming over in a trade from Kansas City via Cincinnati. Last year, he was cut, then reacquired and finished with 25 receptions.

He had been alternating with Ricky Thompson at one wide-receiver spot opposite rookie Art Monk. The Redskins have one other active receiver, veteran Ken Harrison, who caught two passes last week against Chicago in his first game action of the season.