One of the three top producers of NBC’s “Tonight Show Starring Jimmy Fallon” announced Monday he would step down from his role at the show, giving rise to speculation about whether someone else might be named to help lead the program in days ahead.

Mike DiCenzo, a writer and producer who has worked with host Jimmy Fallon for a decade, said via Twitter that he would leave the program, “one of the toughest decisions I’ve ever made, and one I’ve been grappling with this year. Ultimately, I just felt it was time,” he said. “And thankfully, Jimmy couldn’t have been more supportive or understanding.” DiCenzo has been a longtime creative aide-de-camp to Fallon, helping devise some of his best-known late-night sketches, including one that aired earlier this year in a post-Super Bowl broadcast that featured Fallon doing a lampoon of Bob Dylan singing lyrics that described America under the Trump administration.

A person familiar with the matter said talks had begun that could potentially bring a new executive into the mix of running the show. Katie Hockemeyer and Gerard Bradford, two of the other “Tonight” showrunners are expected to stay with the program. A Deadline report Monday suggested Jim Bell, the veteran NBC News and NBC Sports producer who currently oversees NBC’s Olympics productions, could be in discussions to join “Tonight.” Bell could not be reached for immediate comment.

“Tonight” has typically won the most viewers in late night in the audience most coveted by advertisers – people between the ages of 18 and 49. But it has been outmaneuvered in total viewers by CBS rival “The Late Show with Stephen Colbert” for many months. And in recent weeks – the five days ended October 12, for example – Colbert’s and Fallon’s programs tied in the demo, which has long been a benchmark scrutinized by NBCUniversal CEO Steve Burke.  Colbert has delved more deeply into political humor and is not shy about poking fun at President Donald Trump, while “Tonight” host Fallon has worked more diligently to offer a program filled with a broader palette of humor.

Speculation around Bell suggests NBC might be eyeing the strategy that has helped boost fortunes at its late-night CBS competitor. In the Spring of 2016, after Colbert’s program had gotten off to a rocky start, CBS named Chris Licht, a TV-news veteran who helped start both MSNBC’s “Morning Joe” and CBS News’ “CBS This Morning” as the “Late Show” showrunner. Since that time, Colbert;’s program has not only honed in on humor based on the latest headlines, but it has also cultivated guests enmeshed in the latest swirl of the news cycle, whether it be a person at the center of a story, such as Anthony Scaramucci or Billy Bush, or any number of TV anchors, such as Jake Tapper or Joe Scarborough and Mika Brzezinski.

More to come…