NFL commissioner Roger Goodell holds news conference ahead of Super Bowl | USA Today

NFL commissioner Roger Goodell sent a memo to all 32 NFL teams saying that efforts to diversify the league’s coaching ranks have produced “unacceptable” results and added that the league will look into allegations of tanking.

The memo comes days after former Miami Dolphins head coach Flores filed a proposed class-action lawsuit alleging racial discrimination in hiring practices.

The NFL, Dolphins, New York Giants and Denver Broncos were named as defendants in the lawsuit, in which Flores says those teams conducted “sham” interviews to satisfy the Rooney Rule, which mandates that teams interview minority candidates for head coaching and front office positions.

» Subscribe to USA TODAY:
» Watch more on this and other topics from USA TODAY:
» USA TODAY delivers current local and national news, sports, entertainment, finance, technology, and more through award-winning journalism, photos, videos and VR.