"I think they're super hot together," Hyland, 23, told PEOPLE at the fourth annual Celebration of Dance Gala presented by The Dizzy Feet Foundation on Saturday in Los Angeles.
Vergara, 42, was first linked to the True Blood hunk in early July. Another Modern Family costar, Julie Bowen, has also said she approves of the relationship, telling ET Canada, "They are just too good looking."
Hyland, who has known Manganiello, 37, for a "long time" (ever since he played her boyfriend Matt Prokop's dad in an episode of Medium, says he is "divine" and an "amazing person."
"I love him individually," she said of the actor, who was recently named PEOPLE's Hottest Bachelor. "Him and Sofia together – I'm all for it. They'll have really hot babies. I give my stamp of approval on Joe."
Hyland has more on her mind than her costar's romance. The actress is set to star in the musical Hair at the Hollywood Bowl in Los Angeles later this summer. Although the '60s-era show is known for some nudity, don't assume Hyland will be baring it all on stage.
"No, I am not [getting naked]," she said. "I can not speak for anyone else, but I am definitely not."
Reporting by MATTHEW COLE WEISS