While National Football League club owners are still trying to cope with The Era of the Renegotiated Contract, there is a development causing a more alarming concern -- group holdouts.

Dan Rooney, boss of the Pittsburgh Steelers, poses the question: What if an agent with several clients on the same club uses that as a bargaining weapon?

"An agent or agents in such circumstances conceivably could affect the title races," Rooney says. "It would not be fair to all clubs if some teams were targeted for group holdouts while others weren't." Several clubs have had clusters of holdouts this season.

Coach Bill Walsh is newly affirmed as a developer of quarterbacks. Steve DeBerg and Joe Montana of the San Francisco 49ers, a 2-14 team last season, finished this exhibition season with pass completion averages of 79 and 75 percent, respectively, for a 3-1 record in the preseason. DeBerg indicated his average wasn't a fluke when he completed 21 of 29 throws for 72.4 percent in their 26-23 upset of the New Orleans Saints in the regular season opener. It ended an NFL record of 18 consecutive losses on the road.

The Baltimore Colts will have a sellout when the Pittsburgh Steelers visit on Sunday, their first since the Redskins played there in 1978.

Add to the list of blacks joining NFL staffs Clyde Powers, former New York Giant and Kansas City Chief defensive back who was recommended as a scout by John Symank, defensive backfield coach of the Colts, who had been Powers' coach with the Giants.

The power of prayer: cornerback David Waymer, No. 2 draft choice of the Saints, told the New Orleans Touchdown Club, "After all the cold weather I endured at Notre Dame, I asked the Lord to send me to a team in the South or a team with an indoor stadium. Lo and behold, he sent me both."

Unchastised after picking the Redskins to beat Dallas by seven points, the tip sheet SCORE says, "After shutting down the New York Jets' explosive offense on the road it shouldn't be that hard to hold down the Steelers in Baltimore in what figures to be a 'letdown' game for Terry Bradshaw and company. The Steelers know they're home free in the AFC Central."

Coach Bum Phillips of Houston has another view. "Nobody runs the ball against Pittsburgh. We will try to run against other teams," said the fellow who has Earl Campbell for that specialty. He got 57 yards in 13 carries against the Steelers in the opener.

Describing the difference between former quarterback Dan Pastorini, now at Oakland, and present leader Ken Stabler, Phillips says, "Stabler begins reading the field from 25 to 50 yards and Pastorini first looks 50 yards and then back to 25. Some quarterbacks throw high, Stabler hits his receivers right on the numbers." He has a career pass completion average of 60.0.

Even his intercepted passes are accurate. On Sunday three of his five interceptions resulted from deflections. Had those three not gone awry and nine other throws not been dropped he would have had 36 completions in 43 attempts in the loss to Pittsburgh.

Outsiders may be surprised to hear that sudden domestic bliss helped the Steelers to beat the Oilers on Sunday. Bradshaw had dropped from 228 to 201 pounds during training camp, when wife Jo Jo Starbuck had filed for a divorce. When she telephoned him on the Tuesday before the game to say that she had changed her mind and was coming to Pittsburgh, he suddenly became ebullient and forgot about a virus and assorted allergies, leading the Steelers to think his ailments were psychosomatic.

"It's like a honeymoon every time they patch up," an organization man observed.