Game On is the song in question and was used as the 2018 theme for NBC’s Sunday Night Football (SNF) weekly broadcast.
The lawsuit was launched by American country singer Heidi Merrill — who was the supposed primary songwriter, among three others — in Manhattan Federal Court, according to the Associated Press.
After releasing Game On under her own name in March of 2017, Merrill allegedly pitched the song to Underwood’s producer during a conference in Nashville, Tenn., that August.
She was rejected via email by the producer’s assistant, the Associated Press reported. “I’m sorry, we’re going to have to pass,” they reportedly replied in October 2017.
Underwood’s “version” was released more than a year later in September of 2018. It debuted and featured as the NBC Sunday Night Football introduction theme ahead of 17 NFL games that season.
Merrill and the three additional, and undisclosed, songwriters allegedly marketed the song in a way that would allow Game On to be licensed for broadcasts of sporting events.
The lawsuit further claims that Underwood, NBC and the NFL violated a copyright claim on the song, which protected it from “exploitation without compensation to the original author,” according to Merill’s attorney.
WATCH: Heidi Merrill’s ‘Game On’
According to Merrill, Underwood’s Game On is “substantially — even strikingly — similar, if not identical” to her own. The document highlights that the two songs also share the same name, as well as a similar tempo and overall beat.
Her attorney added that Underwood’s Game On debuted with “substantial musical similarity” to Merrill’s Game On.
The lawsuit seeks unspecified damages set to be determined at trial.
Merrill’s attorney concluded to Global News that they “will press forward with our litigation as swiftly and aggressively as possible to prove the truth of our claims and, ultimately, vindicate our clients’ rights.”
Global News has reached out to NBC and Carrie Underwood’s publicist. The NFL declined to comment.