U.S. Ambassador to Germany Richard Grenell is a name to watch as speculation commences on who will replace outgoing United Nations Ambassador Nikki Haley, a source with knowledge of the administration's thinking told the Washington Examiner.

"He's a family favorite," the source, who spoke under the condition of anonymity, said of Grenell.

[READ: Nikki Haley's letter of resignation]

Multiple members of the White House communications team did not respond to immediate requests for comment regarding Grenell being a potential replacement for Haley.

Grenell spent eight years serving as a U.S. spokesman and political appointee to the U.N., making him the longest serving appointee at the U.N. in history. The ambassador served as the U.S. spokesman during many of the most contentious and troublesome periods in recent decades. Grenell ran communications during the war on terrorism, ongoing conflicts in the Middle East, and the U.N.'s oil-for-food corruption scandal.

[Also read: Here are the notable Trump aides who have left the administration]

The president was livid with Senate Democrats for what he felt was slow-walking Grenell's confirmation earlier this year. He said in March that his nominees were "being blocked and/or slow walked by the Democrats in the Senate." Roughly one month after his tweet, Grenell made it through the Senate confirmation process.

Another factor that could put Grenell's name toward the top of the Haley replacement list is the fact that he has a close relationship with national security adviser John Bolton. Grenell served with Bolton, who has held the post of U.S. ambassador to the U.N. previously, in former President George W. Bush's administration. He also served as an adviser to Bolton during the Bush administration.

The president also has an affinity for men and women who have an Ivy League education. Grenell received a Master’s Degree in Public Administration from Harvard University’s John F. Kennedy School of Government.

Haley formally announced her resignation Tuesday morning and will be out of her top diplomatic post by the end of the year.

President Trump accepted the former South Carolina governor's resignation after the pair discussed her departure during a White House visit last week.