Campbell, who missed most of his rookie season with multiple injuries, immediately grabbed his left knee after being tackled.
The Colts receiver did not tear his ACL and will have an MRI on Monday to determine the full extent of the injury, according to NFL Network's Ian Rapoport.
The sophomore wideout was one of Indy's lone bright spots from the Week 1 loss to the Jacksonville Jaguars. He racked up a team-high 71 yards on six catches.
Campbell, a second-round pick in 2019, was widely expected to play a major role in the Colts' offense and appeared to have strong chemistry early with quarterback Philip Rivers.