"#HereWeGo #thegoodwife," she captioned a photo of herself in a Steelers jacket and scarf.
Manganiello shared pictures from the outing on his own account, including a snapshot of his black and yellow socks. He also posted a photo of himself with brother Nicholas Manganiello from inside Gillette Stadium in Foxborough, Mass.
"#HereWeGo @Steelers @NFL #AFCChampionship #ARMAGEDDON," the star wrote.
"He's not a fan. He's, like, obsessed," the star said of her husband. "He's like a sick person. I think it's one of the most important things in his life. Not just football, the Steelers. The Pittsburgh Steelers."
"He has a section in his clothes that is all, like, Pittsburgh Steelers outfits. After two years, it's like he's brainwashed me [into being a fan]. I have no choice," she joked. "I've learned to accept it, but at the beginning it was kind of weird."
Vergara and Manganiello married in November 2015 after more than a year of dating. The actress plays Gloria Delgado-Pritchett on Modern Family, while Manganiello is known for One Tree Hill, True Blood and the Magic Mike movies.