Bill Kilmer, describing himself as "the old knuckleball reliever coming in trying to do what he can," makes his first start of the 1978 season for the Redskins today at RFK Stadium against the San Francisco 49ers at 1 p.m. (WDVM-TV-9).

For the first time yesterday, Redskin Coach Jack Pardee, who still would not officially announce the switch from Joe Theismann to Kilmer, explained precisely why he would make such a move.

"Bill's the fighter, the make-doer, the make-what-you-can guy," Pardee said, "and that's the type of thing we need to get going."

Kilmer insisted on downplaying the quarterback switch that has been the talk of the town all week.

"I'm kind of tired about talking about this quarterback thing," Kilmer said. "You guys (reporters) have blown this thing out of proportion. We're lucky to have two quarterbacks who can play here. All I'm interested in is winning.

"You can just consider me a bull-pen pitcher coming in with a knuckle-ball. How do I know how I'm going to play, or if I'm going to play. My main concern is helping us win, no matter how."

Kilmer once again handled all of the offensive work in the Redskins' abbreviated, hour-long workout at Redskin park yesterday, a practice that also featured two fresh faces in attendance.

Team President Edward Bennett Williams showed up to watch the session and had a pre practice chat with pardee. Asked what he thought about the switch in quarterbacks, Williams said, "That's not my department. I'n in charge of sales."

Running back Mike Thomas also participated in his first practice since Oct. 11, jogging on his own and lining up in the backfield for a half-dozen plays.

Thomas said X-rays taken Thursday of his sore right foot indicated that the oh-so-slight fracture on the top of his foot has "cleared up a little" and "it felt good enough to run today."

Could he play against the 49ers?

"I didn't say that," he said."It's a nagging kind of pain and it's not as strong as I'd like it to be. I'm going to warm up with the team and I'll leave it at that feel a lot better about it now than I did before."

Pardee said he did not plan to use Thomas today unless an emergency arises, the same status he gave tight end Jean Fugett. Pardee said he probably would start rookie Tony Green at tailback and alternate him with Benny Malone, and that Reggie Haynes, who has not caught a pass this season, will start ahead of Fugett.

"Am I due?" asked Haynes. "Geez, it's been eight games and I'm still looking to catch one.Why? Well, I've spent a lot of time blocking downfield. I'll be thrilled if I get one catch and grade out 80 percent on my blocking, just as long as we come out with a big old victory."

The oddsmakers say the Redskins are favored by 10 1/2 points to do just that against a 1-7 49er team off to its worst start since 1963.

Certainly the Redskins have enough incentives. They have played poorly for most of the last three weeks, losing their last two games. They also know a victory would give them a 7-2 record - one game ahead of struggling Dallas, 7-3, in the NFC East.

"It's also a game against a team we're supposed to beat," Pardee said. "It's at home and it's one of those weeks where we can't afford to goof up.

"We're in a situation where we can control our own destiny. It's tough when you get behind and have to depen on somebody else. We might as well forget about the playoffs and just win this week. If we don't, we're kidding ourselves."

Pardee also has not been making any jokes in his preparations for a San Francisco team he described as "kinda" scary. They've got two game-breakers in O.J. (Simpson) and (wide receiver Freddie) Solomon.

"It's kind of like the Philadelphia team - a few great ones and a whole bunch of fighters to go with them, guys who play hard and hit hard."

They also are guys who frequently turn over the football, as well, prompting Redskin defensive tackle Diron Talbert to yell over to Coy Bacon yesterday, "C'mon, let's go practice fumble recoveries."

San Francisco has lost 14 fumbles and quarterback Steve DeBerg, a 42 percent passer, has been intercepted 16 times. The offense is ranked 12th overall among NFC teams, and the 49ers are 14th in total defense.

"I don't care what their stats show, they still have O.J.," insisted Redskin linebacker Brad Dusek, who will have two new players on his side of the field today. Karl Lorch will replace Ron McDole at left defensive end, and Gerard Williams takes over for injured Lemar Parrish at left corner-back, two of five Redskin lineup changes from a week ago.

I don't think we'll have any trouble adjusting to each other," Dusek went on. "I'm more concerned about Simpson. They use him a whole lot of different ways and I don't care what anyone says, he doesn't look like his knee's bothering him.

"He's having a damned good year (532 yards rushing, with 19 receptions for 155 yards more). He's still got that explosion. You think he's not moving and all of a sudden KA-BOOM, he's gone. We just have to play well ourselves, though, and not worry about anything else."

Center Bob Kuziel said, "I don't think there's any divisiveness because of the quarterback change. Jack Pardee wants to win the game and he's doing what he thinks is necessary to do that. It's his decision to change personnel and it's our business to make sure it works. I believe will."