The Dallas Cowboys clinched a wild-card spot in the National Football League playoff's today, but might have lost Tony Doresett in their drive toward the NFC East title that will culminate against the Redskins Dec. 16 in Dallas.

Dorsett "slightly separated" his right shoulder in the second quarter as the Cowboys defeated the Philadelphia Eagles, 24-17, and denied the Eagles a chance to nail down the divisional title. Both teams, however, will be in the playoffs. Dorsett's availability for the Redskin game was listed as "questionable" by the club physician.

Roger Staubach's 17-yard pass to wide receiver Butch Johnson, playing in place of injured Drew Pearson, provided the Cowboys a 24-10 lead with 10:14 left in the fourth quarter.

Then, after the Eagles narrowed the gap to a touchdown on Wilbert Montgomery's second touchdown, Harvey Martin made the big defensive plays that dashed the Eagles' chances.

On second and eight at the Dallas 38-yard line, Martin batted back a pass by Eagle quarterback Ron Jaworski. On second and 10 at the Dallas 17-yard line, Martin's pressure hurried Jaworski into a wayward throw, and on third and 10, he sacked Jaworski for a 12-yard loss.

On fourth down, reserve linebacker Guy Brown hurried Jaworski and he threw incomplete behind wide reciever Harold Carmichael. The Cowboys got the ball and ran out the clock.

Dr. Pat Evans, the Cowboy team doctor, described Dorsett's injury as "a slight separation of the right collarbone . . . the shoulder. It is just a matter of getting rid of the soreness and working him back into practices until he can do full duty. There probably will not be a decision on whether he can play on Sunday until Friday."

Dorsett was hurt on a pass play. He was hit and fumbled the ball away on the Eagle 23.

"I came down in an unusual way, on my shoulder, not on my shoulder pad," Dorsett said. "Will I play against Washington? I wouldn't miss that game if I had a broken leg. I'll be in our training room early in the morning.

"At halftime I took a pain pill, it was so severe. I got an injection and it took quite a while before it went numb. Needles and I don't get along. I'm afraid of needles. It took a little convincing, until tears came in my eyes. I don't believe it's separated, thank God. The X-rays were negative. But it's pretty sore," he said, wincing as he put on his socks.

The doctor said he gave Dorsett medication on the sideline, iced down the injury and put Dorsett's arm in a sling, "but he didn't want to wear it."

Evans said strong safety Randy Hughes dislocated his right shoulder and is "questionable" for the Redskin game, too.

Coach Dick Vermeil of the Eagles was yelling at the officials during their last drive, on first and 10 at the Dallas 17-yard line.

He was upset because wide receiver Carmichael told him the Cowboys had 12 defenders on the field on the play, as quarterback Jaworski was rushed hard by Dallas defensive tackle Dave Stalls and overshot tight end Keith Krepfle deep in the end zone.

The Cowboys had been penalized for having 12 men on the field on the conversion by Rafael Septien in the third quarter that raised their lead to 17-10. But no call was made in the fourth quarter, despite Vermeil's tantrum.

Dorsett carried the ball nine times for 36 yards before leaving the game in the middle of the second quarter.

Rookie Ron Springs of Ohio State replaced him and gained 62 yards in 12 carries. Robert Newhouse gained 68 yards in 12 carries, though he is recovering from a stress fracture in his right leg and was limping in the dressing room. His 17-yard touchdown run down the sideline in the third period gave Dallas a 17-10 lead.

Winds gusted 35-45 mph, but Staubach managed 11 completions in 21 attempts for 105 yards, with no interceptions. He was sacked twice.

Jaworski, the Eagles' "Polish Rifle," looked as though he was discharging popcorn from a popgun at times and hit on only five of 19 throws in the first half. Sometimes he overcompensated for the wind, but he was right on target with a 14-yard scoring throw to running back Montgomery in the second quarter that tied the score at 10-10.

Montgomery ended up with 65 yards in 23 carries, including a scoring dive from a yard out in the fourth quarter to cut the Dallas lead to seven. That score topped off a 65-yard drive and threw a fright into the Cowboys.

But Martin went to work to help kill the Eagles' last gasp, and the Cowboys were in the playoffs for the 13th time in 14 years.

The Eagles will close out their regular season Sunday in Houston, after having made the playoffs for the second straight season.