Alabama defensive line coach Bo Davis has resigned, coach Nick Saban announced Friday morning.

"Bo Davis has submitted his letter of resignation," Saban said in a statement without identifying the reason behind Davis' resignation. "We appreciate all the contributions he made to the program and wish him and his family the very best in the future."

Davis, who has a longstanding relationship with Saban, had been back at Alabama since 2014 after three years as the defensive line coach at Texas from 2011-13.

Davis was LSU's strength and conditioning coach under Saban, an assistant defensive line and assistant strength and conditioning coach with the Miami Dolphins under Saban in 2006 and the Tide's defensive line coach from 2007-10 before leaving for Texas and later returning to Alabama.

"Bo does a really good job," Saban said of Davis in December. "He's a really good coach. He's got a good relationship with his players. He does a good job motivating the guys. And each one of those guys has played better each year they've been here, each year he's worked with them."

Story will be updated.