"Antonio is obviously an experienced linebacker," coach Mike McCarthy said Sunday. "If you look at the youth of the group, it's something we felt we needed to add.
"These things don't just happen overnight. We're very young at that position."
Burks, a third-round pick, had moved into a starting role after Jake Ryan blew out his knee the first week of training camp. The rookie from Vanderbilt started the first two preseason games and was slated to do the same on Friday at Pittsburgh, where he was hurt before the game even started.
McCarthy indicated the Packers were looking to add linebacker depth even before Burks' injury, which he said Sunday was "better than we anticipated" and "should not be a long-term deal."
"It's a position that we wanted to add experience to," McCarthy said. "And definitely [we have] some young guys there that we feel good about."
Third-year pro Blake Martinez, who tied for the NFL lead in tackles last season, was the only inside linebacker on the roster with any NFL experience after Ryan was placed on injured reserve.
Burks said his shoulder popped out of place.
"I didn't really think much of it," Burks said. "Knew something was wrong, obviously, but I've never had any shoulder issues before, so I didn't really know what I was feeling or any kinds of things like that. Good evaluation, good feedback from the MRI and things like that. Like I said, just taking it one day at a time, trying to get rehabbed and get back as soon as possible."
While running back Ty Montgomery left Friday's game with a foot injury, he said he was fine and that "I'm not injured." However, there is concern about backup offensive lineman Kyle Murphy, who started at right tackle against the Steelers. He sustained a right ankle injury and was seen Sunday in a walking boot.
Morrison, a fourth-round pick from Florida in 2016, started all 15 games he played in last season and made four starts as a rookie. The Colts switched from a 3-4 to a 4-3 defense this season, and Morrison fell to the third string.
Pipkins made the Packers' 53-man roster last season as an undrafted free agent. He appeared in 12 games, mostly on special teams, making one start at cornerback and playing a total of 112 defensive snaps. The Packers loaded up at cornerback in the offseason, signing free agent Tramon Williams and using their first two picks on Jaire Alexander and Josh Jackson.