The Trump campaign announced Tuesday that John McEntee, a former UConn quarterback, would be the new senior adviser for campaign operations.
A White House official told Fox News that McEntee was escorted out of the building on Monday.
The Wall Street Journal first reported on McEntee's departure, citing an unspecified security issue.
Sources also told Fox News that security clearance was not the issue.
On Tuesday, the White House announced that Secretary of State Rex Tillerson was leaving his post, to be replaced by CIA Director Mike Pompeo.