Former Minnesota Vikings coach Brad Childress, who had recently been hired by the Alliance of American Football, abruptly resigned from his post as Atlanta Legends coach.

The Legends, meanwhile, named Kevin Coyle as their new coach to replace Childress.

"Coach Childress has stepped away from his role as head coach of The Atlanta Legends," AAF head of football operations J.K. McKay said in a statement. "We are grateful for his leadership, contribution to building The Alliance, and wish him well in his next endeavour.

"Kevin is an experienced, confident coach that has built a well-respected coaching résumé over the years and is ready to take charge of The Legends."

Coyle coached in the NFL for 17 seasons. The AAF will kick off its inaugural 10-week regular-season schedule on Feb. 9.

"I appreciate this opportunity that The Alliance has given me to work with our 75-players as head coach and prepare them for the upcoming season," Coyle said in a statement. "I have learned a lot from Brad and am thankful for his support in this journey. I look forward to putting together a team that Atlanta can be proud to support and bring the city a championship."

ESPN's Courtney Cronin contributed to this report.