(CNN) The two impeachment witnesses that President Donald Trump fired Friday were quietly planning exits of their own, multiple people tell CNN.

Both Gordon Sondland and Lt. Col. Alex Vindman had seen their standings diminished significantly after they appeared before Congress and under subpoena to discuss the hold on military assistance to Ukraine. Because of that, both had been quietly planning to leave their positions after the impeachment trial wrapped up, three sources tell CNN.

Officials told the President this was likely and advised him to let them just leave on their own so he would spare himself the criticism of firing impeachment witnesses. But Trump didn't want them to go quietly, according to one person familiar with his thinking.

In the end, both were fired within hours of each other last Friday.

Sondland and Vindland -- the ambassador to the European Union and the National Security Council's top Ukraine expert, respectively -- had returned to their roles after testifying, but were cut out of their normal day-to-day activities afterward, according to several people familiar with what happened.