The Hawks continue to discuss the next steps regarding the treatment and timetable of the injury to Al Horford.

The team will seek additional medical opinions before deciding the next course of action, which at some point would involve surgery, for their star player who tore his right pectoral muscle Thursday.

In the release of the news of Horford’s injury Friday, general manager Danny Ferry said the team would do its due diligence before concluding what is best for player and team. That process continued Saturday.

The Hawks list Horford as being out indefinitely, but the injury likely means the center and two-time All-Star is done for the season. Horford attended the Hawks’ morning shoot-around in preparation for Saturday night’s game against the Bobcats. Players said he was quiet but upbeat.

“It’s heartbreaking, heartbreaking,” Paul Millsap said. “You hate it for him. He is having a terrific season. For something like that to occur is tough. It’s heartbreaking.”

For Horford, it’s the second such injury, common in the NFL but rare in the NBA. He tore his left pectoral muscle in the 2011-12 season and played only 11 regular-season games before returning in the middle of the playoff series with the Celtics.

“It’s going to be tough,” Jeff Teague said. “I’m not going to lie to you. It’s going to be tough not having him out there.”

Elton Brand replaced Horford in the starting lineup Saturday. Coach Mike Budenholzer would not commit to the move beyond the initial game. The coach spoke to his team in the morning and, according to players, told them not to try to do too much individually and stay within the system.

“The one thing that Coach said is that he doesn’t want anyone trying to replace Al,” Kyle Korver said. “He doesn’t want anyone trying to do more than they have been doing. We’ve been trying really hard to put in an offensive system and a defensive system. We are going to keep on playing basketball. No one needs to try to be anything extra. We are going to put new guys in his spot and continue to play good basketball.”

Entering Saturday, Horford led the Hawks in scoring average (18.6), rebounds average (8.4), shooting percentage (.567) and blocks (44).

The loss means increased minutes for Brand, Gustavo Ayon and Pero Antic. The Hawks will tinker with different combinations in determining how Horford to replace over the long term.

Budenholzer said the team system, both on offense and defense, makes it easier to replace a player — even one with Horford’s abilities. One skill set can be replaced by another.

“We have to (plug someone into Horford’s role),” Budenholzer said. “We don’t have a choice. I think Elton, Pero and (Ayon) are all unique in their skills. Not to take anything away from Al and his uniqueness. I think that is the challenge for all of us, is to all fit together and find a way to stick with what we are doing.”

The Hawks are third in the Eastern Conference standings. A playoff berth remains a possibility, with only three teams above .500, the Hawks being one of them, with more than one-third of the season over.

The Hawks do not have a lot of team size. The loss of Horford, who battled much taller opposition at center, will make things that much more difficult.

Korver acknowledged that there is a smaller room for error without Horford.

“We didn’t have a large room for error to begin with, for different reasons,” Korver said. “Attention to detail, being prepared every night, are going to be that much more important now. Those are things we can control.”