Art Rooney's Pittsburgh Steelers, of all teams, now have strained relations with the press and John Candelaria of the Pittsburgh Pirates wonders about playing second fiddle to shoulder pads.

Candelaria, a 20-5 pitcher last season with the best winning percentage and earned-run average in the National League, was struggling this season with a 2-6 record at Memorial Day. He finally hit his form with a 2-1 four-hit victory over Philadelphia, ending a five-game losing streak of the Pirates.

At the same time, Steeler Coach Chuch Noll, apparently very dissatisfied with the 9-5 record in 1977 and a first-round playoff loss, ordered his players to wear shoulder pads during a minitraining camp and had them hit the blocking sled. Using pad at camps like this is against NFL rules.

A sports writer checked with the National Football League, its Management Council and the NFL. Players Association to be sure the pads were illegal. A representative of the club tried to dissuade the reporter from writing the story, but failed.

The resulting repercussions overshadowed Candelaria's performance. Some letters to the editor likened the reporter to a traitor. Other backed his objectivity. Columunists supported the reporters. Some broadcasters, not to mention Candelaria, backed the Steelers, discounting the news value of the incident.

There were hints that the Steelers, who have had wide-open accessibility for the press, will impose restrictions. The Steelers expect to be fined by the league or have a draft choice taken away. It was recalled that New England was reprimanded for the same violation a few years ago. Sources say two other clubs have used shoulder pads in mini-camps this spring.

When George Allen was asked if he would represent his son, Bruce, a kicker, in negotiating as a 12-round draft choice with former Redskin assistant Ted Marchibroda of the Baltimore Colts, the new Rams' coach said, N"o, I will leave that up to my other son, George (who is an aspiring attorney)."

Young Vince Lomardi, now 36, is back in the East as assistant executive director of the NFL Management Council. He had been director of ticket sales and marketing for the Seattle Seahawks.

An attorney and former member of the Minnesota legislature, he says of his previously stated goal of becoming a general manager for some club, "I have ambitions, but who knows what's down the line? Collective bargaining in pro sports is just not going to go away. I think it will be dynamic, exciting. But I'll miss the adrenalin flowing as it did weekly at the club level (at Seattle)."