Alabama Crimson Tide assistant coach Bo Davis has resigned, the school announced Friday.

Davis' resignation comes in the wake of school and NCAA reviews of potential recruiting infractions, The Tuscaloosa News has reported.

Davis was making $475,000 annually in a contract that ran through 2017, according to the Tuscaloosa report. He spent Thursday working in the Alabama football offices, a team source told ESPN's Chris Low, but he resigned Friday.

In all, he spent six seasons at Alabama and won two national championships.

"Bo Davis has submitted his letter of resignation," Alabama coach Nick Saban said in a statement Friday. "We appreciate all the contributions he made to the program and wish him and his family the very best in the future."

A source told ESPN's Ian Fitzsimmons that Davis "did not cooperate fully with the NCAA investigation," and that was the reason he was asked to tender his resignation.

Davis returned to the Crimson Tide as the defensive line coach in January 2014, a week after being formally introduced at USC in the same role. He had told the Trojans he was leaving for family reasons.

Davis coached defensive tackles at Texas from 2011 to 2013 and spent eight of the nine years before that on Saban's staffs at Alabama, LSU and the Miami Dolphins.

Davis played nose guard at LSU and earned All-SEC second-team honors as a senior in 1992.

Saban had lauded Davis in November, according to The Tuscaloosa News' report.

"Bo does a really good job," Saban said. "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. And we've got some guys that have been playing for a while, and they're really playing well so far this year. Hope they can keep improving and keep playing and keep having an impact on the game."

Information from ESPN's Alex Scarborough was used in this report.