Sen. Ron Johnson (R-Wis.) said today that he expects few staff changes as he shifts his immediate focus from legislation to political messaging.

Senate Minority Leader Mitch McConnell (R-Ky.) has asked Johnson to lead Senate GOP efforts to coordinate its message and agenda with House Republicans and the party’s presidential nominee, likely to be former Massachusetts Gov. Mitt Romney. The departure of Johnson’s legislative director, Robert Duncan, sparked speculation that the Senator would shake up his senior staff to bring in more politically experienced advisers. But Johnson shot down that rumor during a brief telephone interview.

“We’ve had incredibly low turnover in my office,” Johnson told Roll Call.

Multiple Republican sources said more staff changes could be in the offing, including some who said that Chief of Staff Don Kent was on his way out, possibly to be replaced by Ken McKay. McKay, who currently serves as a senior adviser to Johnson in his Senate office, was Michael Steele’s first chief of staff during his tenure as Republican National Committee chairman.

But Johnson said Kent was staying put as his chief of staff, adding that Duncan left of his own volition because he was offered a “good opportunity” to work on the Senate floor. Kent separately told Roll Call that he had no plans to depart Johnson’s office. “Ken and I are working together and having fun. I have no plans to leave,” he said in an email.

Republican insiders say that Johnson, a freshman who ran his own business for three decades before being elected to the Senate in 2010, has been frustrated with the slow pace of action on the Hill and the inability to move legislation. His pivot to messaging and communications is an attempt to have more of an effect, coinciding well at the request of McConnell and other Senate Republican leaders.

Johnson said his skill set from the private sector suits his assigned role as a planner and coordinator, and the Senator added that he hoped his effort would help Congressional Republicans and the GOP presidential nominee compete with President Barack Obama. Johnson said he is talking to “smart people” in the House, Senate and outside the Beltway to seek input on helping to create a “powerful agenda” for Republicans to run on.

Johnson endorsed Romney over the weekend, in advance of Tuesday’s Wisconsin presidential primary. The Senator spoke to the former governor about his messaging coordination plans Sunday, and he said the presumptive GOP nominee was receptive.

“Hopefully, we’ll be able to coordinate our message very closely,” Johnson said. “I believe he certainly understands [the] advantage of having a coordinated message and strategy. I can’t predict success until it happens, but certainly the will is there.”

One Republican insider who monitors the Senate said not to make too much of changes to Johnson’s staff.

The insider said that Wisconsin’s junior Senator hired old hands with Senate experience to help get his office off the ground and to advise the first-time elected official on the intricacies of Congress and legislating. They would likely have moved on in the near future anyway, the source said, adding that it is not uncommon for new Members to replace staff after they’ve determined what area of policy or politics they want to focus on.

“My guess is that some of them are ready to move on and are floating résumés,” the Republican insider said.

Kent praised Duncan’s tenure in a statement.

“Our Legislative Director Robert Duncan left to pursue a great opportunity on the Senate Floor. Robert is a tremendous talent and a good friend. He will be missed. At the same time, we’ve brought on Matt Moon, who will be an asset on policy, legislation, and communications,” Kent said, referring to the new senior adviser. “Senator Johnson has always recognized the critical importance of communicating to the people of Wisconsin and the nation the seriousness of our nation’s fiscal challenges. That remains a top priority.”

Correction: April 3, 2012

An earlier version of this story incorrectly stated Matt Moon’s title. He is senior adviser to Sen. Ron Johnson (R-Wis.).