The team did not disclose the reason. According to the Lightning's website, Hedman is sitting because of an illness.
Hedman, 26, is second on the team to Nikita Kucherov with 38 points. Hedman's 31 assists lead Tampa Bay.
After going to the conference finals last season, the Lightning are sixth in the Atlantic Division. Their cause was not helped by losing captain Steven Stamkos to a knee injury in November.