It has been two months since Carrie Underwood underwent a facial surgery. Recently, the singer teased an upcoming song inspired by what she had endured.

Underwood's injury came about after the country star fell from the stairs at her Nashville home. According to the singer, she needed at least 40 stitches on her face. This was previously kept hidden from public, as her representative previously announced that Underwood injured her wrist with several cuts and bruises.

The former "American Idol" winner then revealed that a worse injury involving her face transpired from the accident after publishing it in a paywall-protected fan site.

"There is also another part of the story that I haven't been ready to talk about since I have still been living it and there has been much uncertainty as to how things will end up," she wrote in the fan site, as reported by Variety's sources.

Underwood's post-surgery look was recently leaked after celebrity chef Adrienne Gang posted on Twitter a photo of herself with Underwood after working on a project together.

While the star has not yet appeared live on stage, Underwood teased fans a song that was inspired by the hardships that she endured during her recovery period. On Jan. 6, Underwood's song "The Champion" was played in a National Football League (NFL) commercial during the Wild Card game between the Los Angeles Rams and the Atlanta Falcons.

Not much is known about the contents of the song, but according to sources of Variety, Underwood is working with "Sunday Night Football" executive producer Fred Gaudelli. The executive producer is reportedly the man in charge of composing the song's tune.

"I think it's going to become a sports anthem," Gaudelli told Variety, adding "It's going to be one of those songs that you see cut to highlights for the next 25 years," he added.

"Champion" is set to officially debut at Super Bowl LII on Feb. 4. Other famous stars such as Pink and Justin Timberlake will also be part of the NFL event.