Retired Gen. Jack Keane says he turned down Sec Def offer — 'Mad Dog' Mattis now leads the pack

Retired four-star Army Gen. Jack Keane was asked to serve as Secretary of Defense in the Trump administration, he said, but he turned it down for personal reasons.

Keane, a frequent contributor to Fox News, told NPR that he turned the offer down because of ongoing "issues" following the death of his wife in June.

"I was asked to serve, but I'm not able to," Keane told NPR's Rachel Martin. "I have some personal issues surrounding the death of my wife recently, and I explained all that to Mr. Trump, and he was very gracious and understanding, and quite supportive."

Keane said he recommended Marine Corps Gen. James Mattis and former CIA Director David Petraeus to lead the Defense Department in his stead.

"Mad Dog" Mattis, as he's known within military communities, is now reportedly the top candidate for the post, which is currently held by Defense Secretary Ashton Carter.

Mattis' consideration has already caused some controversy in political and military circles — especially because his outspokenness often matches Trump's, like in 2005 when he said that it can be "fun" to shoot people.

Trump reportedly met with Mattis Saturday and on Sunday tweeted his admiration for the general.