Gustavsson left Saturday's 4 Nations Face-Off game against Finland after the first period due to an illness, Dan Rosen of NHL.com reports.
Gustavsson allowed two goals on four shots in 19:46 of playing time before being replaced by Linus Ullmark. Ullmark stopped 15 of 17 shots in relief in Sweden's 4-3 overtime loss to Finland. Gustavsson could play in Monday's road game versus Team USA if he's feeling better, but Ullmark and Samuel Ersson are available if needed.