Bandmates Tyler Hubbard and Brian Kelley haven't been shy about their desire to work with the country superstar, and even sent out a public appeal via social media in February.
"Whether you know it or not, we are huge fans of you and we have always wanted to do a song with you," they posted on Twitter.
Referring to a track they had created with singer/songwriter Julia Michaels, the "Cruise" hitmakers continued, "We'd really love for Carrie Underwood to hear this song. We think it would be a massive collaboration. We'd love to send it to you."
The pair went on to preview the tune, in the hopes Carrie would be shown the Twitter plea, explaining, "We don't have your email or your phone number, so we're gonna just play a little."
Carrie didn't publicly respond at the time, but Hubbard and Kelley have since revealed she did reach out about the track.
"We got turned down on that one," Hubbard explained during a recent appearance on the CMT Hot 20 Countdown chart show.
"You don't win 'em all. I guess she didn't love it as much as we did, but that's alright," he joked.
Hubbard then shared the real reason behind the failed collaboration request: "I think she said it was amazing and she'd love to, but it was right around her book tour release and so she was super busy and didn't really have time," he recalled. "But who knows, who knows where it will go. Now it's just open game."
Carrie launched her self-help book, "Find Your Path: Honor Your Body, Fuel Your Soul, and Get Strong with the Fit52 Life", in early March.