It will be a short week for the Houston Oilers to get ready to play the Chargers Saturday in San Diego, but a long, long week of suspense.

That is because quarterback Dan Pastorini severely pulled an abdominal muscle and Earl Campbell mildly pulled a groin muscle today while the Oilers were eliminating the Denver Broncos, 13-7, in the wild-card playoff game of the American Football Conference.

Dr. Robert H. Fain, the Oiler club physician, said Campbell probably will be able to play in the second round of the postseason competition but said of Pastorini, "There's no way I can tell now."

Campbell, who sat out the second half after being hurt while scoring the go-ahead touchdown, said he was sure he would be able to run. Pastorini, while limping in the dressing room, replied, "What can I tell you after what the doctor said?"

Houston Coach Bum Phillips said, "We probably won't be able to make a decision on them until Wednesday or Thursday." Meanwhile, he said, he would get Gifford Nielsen, who finished up for Pastorini, ready.

Campbell was injured three plays before the end of the first half as he spurted out a full-house T formation and scored from three yards out behind the block of Tim Wilson.

Campbell fumbled as he entered the enzone and apparently instinctively, he frantically dug in to retrieve the ball, though it was not necessary because once the ball reaches the goal line it is touchdown.

Campbell was hit as he fumbled and his again as he scrambled on the artificial turf for the ball. He rolled over in pain, clutching his upper thighs. He left the field before the half ended and watched the second half from the Houston bench.

Pastorini was injured in the third quarter, without being hit. He was running to his right to get away from defensive pressure, and dug in harder just before he went down, his left knee under him. He was helped off the field, his left knee suspended in the air.

Wide receiver Ken Burrough left the game before the half with an aggravation of a chronic tailbone injury but is expected to play Saturday.

Campbell, the Boom Town Boomer, had carried the ball 16 times for 50 yards. Pastorini had completed eight of 18 passes for 149 yards, had been sacked once and intercepted once.

Nielson threw only four passes, completing two for nine yards, and was intercepted once. He said he was instructed to play conservatively, which he was able to do because of "how intensely" his teamates raillied around and encouraged him.

It was the defense that aroused itself at that point to project the 10-7 lead Pastorini had turned over to Nielsen. And Place kicker Toni Fritsch gave the defense a little more of a cushion with his second field goal, from 20 yards in the fourth quarter.

With the 31-yarder he booted in the first quarter, Fritsch now has a remarkable record of 23 field goals in 27 attempts for the season.

The defense shut out Denver the last three quarters and demoralized quarterback Graig Morton by intercepting him with 7 minutes, 49 seconds remaining and sacking him six times.

Coach Red Miller, asked if he had considered changing quarterbacks, replied, "No, Morton got us this far and he's the best thrower we've got. Sometimes his protection broke down, sometimes Morton held the ball too long. It was a lot of things. You cannot win too many games with seven points."

Miller said the pivotal play was the pass intercepted by linebacker Gregg Bingham, who ran the ball 15 yards to the Denver 20. Five plays later, Fritsch made the score 13-7.

Denver was eliminated from the playoffs in 1978, as the AFC West champion, by Pittsburgh.

Today the Broncos were coming off a 17-7 loss to San Diego on Monday night. Nevertheless, Miller put in a double tight end offense and the Broncos took a 7-3 lead in the first quarter as Morton took them 80 yards, completing four of five passes, the last a seven-yard scoring throw to running back Dave Preston.

He had seven completions in 11 attempts in the first half, but finished with 14 for 27.

Pastorini missed on six of his first eight throws, but set up Fritsch's first field goal by going 64 years, mostly on a pass interference penalty and a 41-yard pass to running back Ron Coleman.

Campbell wad thrown for a fouryard loss before Fritsch salvaged three points. Campbell also lost a yard on third and one in the second quarter fourth and one that period after no gain.

Yet it was Campbell thumping the best defense in the National Football League for 17 begrudged final yards, the last three for the touchdown, as the Oilers went 74 yards for their only six-pointer.

In effect, he dragged the Oilers into the playoffs while limping into the end zone.