Despite the positive test, Purdue is continuing with team activities as of now.
Karlaftis was administered an antigen test in the morning, which came back positive, and the result was confirmed with a PCR test. The school says Karlaftis is now at home in isolation.
He could be eligible for Big Ten Champions Week on Dec. 19, the date for the conference championship game and crossover consolation games with the remaining teams in the conference.
Karlaftis, who has two sacks in three games this season, led the team in 2019 with 17 tackles for loss and had 54 total tackles and 7.5 sacks.