As he gears up for his second term, Sen. Marco Rubio is making staff changes at the highest level, announcing Monday that he is replacing his chief of staff with a top campaign operative from his presidential and reelection bids.

The Florida Republican said in a news release that Clint Reed will be his new chief of staff, a position that Alberto Martinez has occupied since 2014. Martinez will become a senior adviser to Rubio.

The decision highlights the deep confidence Rubio tends to place in political operatives he trusts and the sharp political eye he appears to want to bring to his office as he moves into the next phase of his career.

“For over a year, I’ve gotten to know and work closely with Clint on my campaigns, including two in Florida. He’s a superb manager who loves Florida, has earned my trust, and relishes the challenge of solving tough problems,” Rubio said in a written statement.

Martinez, Rubio said, “will continue to play a key role in shaping our office for the new challenges and opportunities which lie ahead.”

Reed, a longtime political operative from Arkansas who has worked for the Republican National Committee, impressed Rubio with his management of the Floridian’s presidential effort in Iowa, among other things. Rubio came in third in Iowa, one of his better showings in a Republican primary in which he struggled to build a following and eventually bowed out of after getting blown out by now-President elect Donald Trump in the Sunshine State.

Rubio’s associates have said that he intends to emerge as a leading figure on Capitol Hill in the areas of foreign policy and national security beginning early in his second term. The Florida Republican is on the Foreign Relations Committee.

Rubio is at the center of a key nomination battle coming early next year. He has expressed concerns that Trump’s nominee for secretary of state, Rex Tillerson, is too close to Russian President Vladimir Putin. The senator has heard directly from former vice president Richard B. Cheney and other influential GOP figures seeking to persuade him to back Tillerson.

Rubio campaigned for president as a traditional Republican hawk, skeptical of the Russian government’s intentions.