Since taking up his post in March, Reeker has spent a significant amount of time interacting with Sondland and dealing with Ukraine policy, according to officials with knowledge of his schedule. Reeker also holds a direct line to senior officials at the department including David Hale, the under secretary for political affairs, as well as Secretary Pompeo. During the effort to oust Yovanovitch, Reeker reportedly relayed concerns by George Kent, his deputy, about the campaign to Hale.

In his testimony earlier this week, William Taylor, the top diplomat in the country, said President Trump, in a phone call with Sondland, said Ukrainian President Volodymyr Zelensky had to “clear things up and do it in public” before the shipment of military aid to Ukraine. Individuals familiar with Reeker’s plans say the career diplomat is likely to confirm parts of Taylor’s testimony as it relates to Sondland and Yovanovitch.

“I have a feeling Phil will go in there Saturday and do exactly what Taylor said,” the State Department official said.

Even before he assumed his current role, Reeker occasionally worked with Sondland.