GOP presidential contender Ben Carson is firing over half his staff on Thursday, citing financial issues, according to The Washington Post.

The former neurosurgeon, once a top tier candidate but struggling to keep up in recent months, will let go over 50 of some 125 staff members, most of who work in field operations and at his campaign headquarters in Northern Virginia.

Many of those spared will have their salaries reduced, while the number of traveling advisers is also being cut and Carson may start flying commercial rather than privately. His most senior staffers will stay on board.

A campaign source said the changes will help Carson's campaign "focus their energy a little bit more" on the upcoming primaries in New Hampshire and South Carolina.

"Dr. Carson is going to get his campaign lean - really lean," longtime Carson confidant Armstrong Williams told The Post. "One issue for a while has been too much infrastructure, and he has decided to fully address it so that he can sustain his campaign until the convention."

The decision comes after Carson finished fourth in the Iowa caucuses on Monday, with less than 10 percent of the vote.

Williams said that Carson is still angry at Sen. Ted Cruz, who won the Iowa caucuses, for circulating rumors as the caucuses were underway, saying that Carson was withdrawing from the presidential race. Carson said he was actually only leaving Iowa to get a "fresh change of clothes," according to CBS News.

In New Hampshire, where primaries will be held on Feb. 9, Carson is in last place with just three percent, according to RealClearPolitics' average. Speaking on Wednesday before the staff cuts had been announced, Carson said that he plans to continue campaigning for the foreseeable future. "One of the things they say represents America is baseball," he said, reported TIME. "Have you noticed in a baseball game, there are nine innings and you don't call the game after the first inning or two? There's a reason for that."