John Delaney. (NIKKI KAHN/THE WASHINGTON POST)

“Our campaign has grown significantly and rapidly across the Sixth District,” Delaney spokesman Will McDonald said in an e-mailed statement. “As a result, we have added Justin Schall to the team as Campaign Manager. Justin is an experienced veteran of numerous campaigns and brings a breadth of experience to the team. Max Cummings remains an important and valuable part of the team, working closely with John to assure a winning campaign.”

Schall has worked on several Democratic campaigns in the past, including Tom Henry’s 2011 bid for mayor of Fort Wayne, Ind., and John Callahan’s campaign for Congress in Pennsylvania in 2010.

The status of Cummings, who will remain on the campaign payroll, has been a bit of a mystery since the Baltimore Sun asked Monday whether he was still in his job and did not get a clear answer in response.

Delaney is currently battling with state Sen. Rob Garagiola (D-Montgomery), physician Milad Pooran and two other candidates for the Democratic nomination in the seat currently held by Rep. Roscoe Bartlett (R). Much of the campaign has been negative, with Delaney accusing Garagiola of hiding his past work as a lobbyist and Garagiola attacking Delaney for donating money to Republican Rep. Andy Harris (Md.).

A newcomer to electoral politics, Delaney has pledged to spend significant sums from his own money on the race. In addition to his paid campaign staff, Delaney has also enlisted the services of pollster Fred Yang of Garin Hart Yang Research Group and consultant J.B. Poersch of SKDKnickerbocker.