ET's Lauren Zima caught up with the actress at the AGT season 15 kickoff at Pasadena Civic Auditorium on Wednesday, where she dished on diving head-first into her new role as a judge -- which apparently included already awarding her Golden Buzzer.
"I did, I couldn't help myself! I don't know why, it was like something I felt inside and I felt it was right," she shared. "It was on my first day. So, I was like, 'I don't know who the hell I think I am, but I know already.'"
"But I think I made the right choice," she added. "I think the people are gonna watch it and think that person deserved it."
For Vergara, being a talent judge isn't something she ever thought of before signing on.
"I never, in my life, expected to do something like this. I've never done anything like this," she shared, adding that she was hesitant at first when AGT producers approached her.
"I [was like], 'Wait, I have to think about this, I don't know if I can, you know, be a good judge or whatever. And the more I thought about it, I thought, 'You know what? This actually sounds like a group of people that I could be part of."
"It seemed like the right thing to do after eleven years of Modern Family," she added. "To mix it up, you know?"
According to Vergara, she talked the decision over with her manager and her family -- including husband Joe Manganiello, who had a lot of support for the possibility.
"He got very excited!" she recalled. "He was like, 'Of course! You're perfect for that. Just be yourself and you're gonna be OK.'"
"Everybody was like, you know, either in a bad mood or we were like, super sad crying," Vergara recalled. "It was about the family we created for 11 years, and I'm never gonna see them again like that. Some are people that are never gonna see again in my life, you know, crew members that we saw every day for 11 years. So that's the sad part, the separation from those people."
However, with AGT, Vergara has an opportunity to build new friendships and connections with her fellow judges, including host Terry Crews.
"We had humble beginnings in a little movie called Soul Plane," Crews recalled to ET. "We were all just starting out, trying to make it in this business and I watched her become one of the most famous women in the world… It feels like serendipity, the fact that we're working together now, doing something like this."
Fellow judge and series creator Simon Cowell also opened up about having met with Vergara several years ago, hitting it off, and looking forward to an opportunity to work with her on something in the future.
"So, when her name came up, I called her and I said, 'I'm praying this is going to work out,' and she said, 'Actually, Simon, the timing is perfect!'" he recalled.
Cowell also explained how she was a bit nervous, at first, but he shared some sage advice from his years as a judge on the show.
"I told her, 'If it's any comfort, nobody is qualified to judge every kind of act, because the variety is so huge. You just got to go with your gut feeling and have fun,'" Cowell said.