Terry Long of the Pittsburgh Steelers, a veteran offensive guard and one of the National Football League's strongest players, was in Allegheny General Hospital today, two days after he reportedly tried twice to commit suicide.

Long was distraught about an impending suspension for failing a steroids test and over possibly losing his starting job, several teammates said. They said Long had told them he learned Tuesday he had failed a steroids test administered on July 11, the day after the team reported to training camp at St. Vincent College in Latrobe, Pa.

Not only was Long worried about the steroids test, they said, but he was also concerned about being beaten out by Carlton Haselrig, who was a 12th-round draft choice in 1989. With Long limited by a hamstring injury, Haselrig has been practicing with the Steelers' starters. 'Just Hope He's All Right'

"I'm real concerned about him," Dermontti Dawson, a teammate, said. "I just hope he's all right."

According to people familiar with the incident, Long, 32, started a car in a closed garage at his home in Franklin Park on Wednesday when the Steelers were practicing with the Washington Redskins.