Dr. Ben Carson is sitting out the next four years of Donald Trump’s administration ― at least officially.

Carson, a onetime Republican candidate for the presidency, will not seek a position in Trump’s Cabinet “or any position in the administration,” Carson adviser Armstrong Williams told Politico on Tuesday.

“Dr. Carson feels he has no government experience, he’s never run a federal agency,” Williams told The Hill. “The last thing he would want to do was take a position that could cripple the presidency.”

Carson’s name has been floated as a potential pick for either secretary of education or secretary of health and human services. Speaking to multiple news outlets on his behalf, Williams said that no specific role had been offered to Carson, but that numerous options were open.

The retired neurosurgeon has never held elected office. He was one of three GOP presidential primary candidates ― the other two being Trump and former Hewlett-Packard CEO Carly Fiorina ― who had no prior political experience.

After Carson bowed out of the primary, he was among the first former rivals to become a Trump backer. In his election-night victory speech, Trump described Carson as a competitor turned true friend.

Carson is still expected to advise Trump in an unofficial capacity.