CBS sitcom Mike & Molly will begin its fourth season without showrunner and creator Mark Roberts.

Deadline reported Friday that showrunner Mark Roberts would be leaving the popular CBS sitcom despite the show being on the schedule for next year.

A spokesman at Warner Bros. TV (the show's production company) stated: "Al Higgins, currently co-executive producer of Mike & Molly, has been named executive producer and will serve as day-to-day showrunner of the comedy for its upcoming fourth season."

Other than Mike & Molly, Higgins has been involved in producing and writing for such shows as Malcolm and the Middle and NewsRadio.

Though neither Warner Bros. TV nor CBS have commented on why Roberts is stepping down, Deadline notes that most of the cast and crew were unhappy with his leadership.

When CBS announced their upfronts on Wednesday, May 15th, Mike & Molly was nowhere to be seen on the fall schedule.  Despite this, the network ordered 22 episodes of the show, just in case one of the new fall comedies fails to catch on with audiences.

The show has aired for the past three seasons in the Mondays at 9:30 pm.  Star Melissa McCarthy (who plays series lead Molly Flynn) won an Emmy for the show's first season in 2010 and was nominated for the show's second season.

The actress received a lot of acclaim for her role as Megan in the 2011 comedy Bridesmaids, garnering an Academy Award nomination and several critic organization awards. 

She recently starred alongside Jason Bateman in the film Identity Thief, which grossed over $130 million at the box office.  She will also star in the upcoming comedy The Heat with Sandra Bullock, which comes out in theaters on June 28th.

Mike & Molly is tentatively set to air in Spring 2014 on CBS.