Andrew Luck’s Civil War-themed parody account, @CaptAndrewLuck, is among football’s most popular Twitter accounts with nearly 500,000 followers thanks in part due to Luck’s stellar return from injury this season.

But an attempt to play off that Twitter page had ESPN issuing an apology on Sunday.

During Saturday’s broadcast of Colts-Texans, ESPN presented a graphic that depicted Luck as a Union general with both apparent Confederate and Union soldiers protecting him. The graphic itself was historically flawed, but the music choice ultimately led to an apology.

Reinforcements along the Colts' offensive line have kept Captain Andrew Luck upright in 2018. pic.twitter.com/4wKsBsdzuH — NFL on ESPN (@ESPNNFL) January 5, 2019

The broadcast played the Confederate anthem, “Dixie,” which had many viewers upset given the song’s obvious connections to racism and slavery.

Soooo we going to act like this didn’t happen @espn can u please explain? I’m an afro American and no I don’t wish I was in dixie.. pic.twitter.com/3iTFXj4CoN — DonaldGodbolt (@gospelmystro) January 6, 2019

Did that graphic of Civil War Andrew Luck have him protected by guys with gray jackets and "Dixie" playing in the background? Is George Pickett running the graphics department at ESPN? — Michael Baumann (@MJ_Baumann) January 5, 2019

Did….. ESPN just play Dixie during an NFL Playoff game? — Richard🇬🇾Johnson (@RJ_Writes) January 5, 2019

ESPN told Sporting News that the song’s usage was an unplanned error by a production staffer. Via Sporting News:

“Dixie” was not part of the graphic when the piece was initially produced and approved, a source told SN. Instead, the song was dropped into the piece at the last moment by a staffer in the production truck. A source said ESPN addressed the issue with the staffer, but would not elaborate on the outcome. “It was a mistake to use this song. We regret having done so and we apologize,” said ESPN spokesman Josh Krulewitz in a statement to SN.

Despite the apology, the tweet of the graphic (with the song) remained on ESPN’s NFL social accounts as of Sunday evening.