A Shakeup in Ben Carson's Campaign: Top 3 Aides Resign

— -- Three top aides to Ben Carson announced Thursday that they are resigning from the Republican presidential candidate's campaign.

Thursday morning, campaign manager Barry Bennett and communications director Doug Watts announced they "have resigned from the Carson campaign effective immediately."

"We respect the candidate and we have enjoyed helping him go from far back in the field to top tier status," Watts told ABC News Thursday. "Having just announced raising $23m for the 4th Q, more than any other Republican candidate, and passing 1 million contributions and over 600k unique donors since March, we are proud of our efforts for Dr. Carson and we wish him and his campaign the best of luck."

Thursday afternoon, ABC News learned that the deputy campaign manager and policy director Lisa Coen also resigned, according to the new Carson campaign manager, Ed Brookover.

Brookover says this is the only additional staff resignation he knows of right now.

In his new role, Brookover, who previously served as Carson's senior strategist, says he will focus his efforts on communicating Dr. Carson's vision and set of values.

"I will continue to put my focus on him and his message moving forward," Brookover told ABC News on the phone. "I am looking forward to serving Dr. Carson in the best way I can and am honored he's placed his faith in me to help his campaign."

Foreign policy adviser, Robert Dees, will function as the campaign chairman.

Carson released a statement Thursday commending Bennett and Watts "for their efforts to help me share my vision for America."

"As we enter a new phase of the campaign cycle, it is necessary to invigorate my campaign with a strategy that more aggressively shares my vision and world-view with the American people," the statement from the GOP candidate read. "I commend Barry Bennett and Doug Watts for their efforts to help me share my vision for America."

The statement also said that the Carson campaign "is fired up about the New Year, recognizing that these positive changes will create even greater effectiveness on behalf of Dr. Carson."

Last week, Carson gave separate interviews to the Associated Press and the Washington Post, the Republican presidential candidate said he was "looking at every aspect of the campaign right now" and that "every job is on the table" in his campaign.

His campaign staff disputed those claims, telling ABC News that it's not true and Carson released a statement saying he has "100 percent confidence in my campaign team."

"I have 100 percent confidence in my campaign team. We have come a long way and accomplished great things together, and together we look forward to winning in Iowa and beyond," the paper statement read. "We are refining some operational practices and streamlining some staff assignments to more aptly match the tasks ahead, but my senior team remains in place with my full confidence, and they will continue to execute our campaign plan."

Appearing on CBS "Face the Nation," Carson said last Sunday the one major change in his campaign strategy would be taking a much more aggressive approach towards attacks -- something he has refused to do so far during his campaign.

The shakeup in Carson's campaign comes before the Iowa caucuses on Feb. 1.