With CBS renewing its long running show "NCIS" for seasons 14 and 15, the series is guaranteed at least another year on air but rumors are persistent that season 15 will be the last seasn for 'NCIS.' 

According to a report by HNGN, there was a ratings drop after popular original character Tony DiNozzo (Michael Weatherly) left the show at the end of season 13 to headline his own show. Weatherly currently stars in "Bull," another CBS show that is loosely based on the life of Dr. Phil McGraw.

Based on a report by Parent Herald, the show's ratings is one of the major reasons fans are afraid that 'NCIS' will be cancelled. Based on the latest figures, the show only got a 1.75 rating from the 18-49 year old demographic, which is 2.78% lower than the previous episode. On average, viewership of the show dropped by 13.35%.

The report cited the possibility that many fans of the show also left 'NCIS' along with their favorite character. It also suggested that with Tony gone, the entire dynamic of the show has changed despite the addition of new characters like Agent Torres (Wilmer Valderrama) and Agent Quinn (Jennifer Esposito) to the team.

Meanwhile, the return of a familiar character for episode 7 has fans excited about the possibility of having Tony return to the show. Episode 7 — entitled "Home of the Brave" — will feature Tony DiNozzo Sr. (Robert Wagner) and it is expected that DiNozzo Jr. could very well pop up within the season to help the show he has been with for 13 seasons.

"Torres boldly breaks protocol when he learns a witness in an NCIS case is wanted by U.S. Immigration and Customs Enforcement. Meanwhile, Abby (Pauley Perrette), Bishop (Emily Wickersham) and McGee (Sean Murray) woo landlord Tony DiNozzo Sr. in hopes of subletting Tony's apartment," read the synopsis for the episode.

"NCIS" airs on Tuesdays at 8 p.m. EDT on CBS.