Donald Trump’s national political director will “step back” from his role overseeing the Republican nominee’s ground game with less than three weeks to go before Election Day, Politico reported Thursday.

With Trump trailing Clinton in a number of critical battleground states and lagging in the polls, this announcement could spell trouble for the campaign’s get-out-the-vote efforts.

“I have not resigned but for personal reasons have had to take a step back from the campaign,” Jim Murphy told Politico in a statement, declining to offer more detail on the reason for his departure.

Politico reported that several Trump aides have expressed concern about Murphy’s absence as the race enters its final days.

Murphy’s retreat is only the latest staffing upset for the real estate mogul’s campaign. The veteran GOP operative came on board in June to replace Rick Wiley, who abruptly left the post after only six weeks on the team after clashing with then-campaign manager Corey Lewandowski.

Lewandowski himself was forced out over his brash managerial style and reportedly tense relationship with Trump’s three adult children, and his successor Paul Manafort also left the campaign after only a few months on the job.