A former “Teen Wolf” actor is appearing in the Season 5 premiere of “Elementary.”

Matthew Del Negro, who recurred as Rafael McCall in Seasons 3 and 4 of the MTV supernatural drama, is guest-starring in Episode 1 of the upcoming installment of the CBS procedural series. Not much is known about his role on the Sherlock Holmes TV series, but according to a press release for the premiere, the 44-year-old actor is playing a character named Nathan Resor.

The Season 5 premiere, titled “Folie a Deux,”  finds Sherlock (Jonny Lee Miller) and Joan (Lucy Liu) joining the NYPD manhunt for a serial bomber who is active again after going dormant for six years. During the investigation, Joan seeks help from her former patient Shinwell Johnson (Nelsan Ellis), who is trying to get his life back in track after a long prison stint on drug charges. Also in the episode, Sherlock senses Joan is unhappy and asks her whether she is still fulfilled by her career as a detective.

It’s unclear how Del Negro’s character will fit in either storyline, but since his name is on the top of the guest stars list for the episode, it seems that he’s playing an important role. Joining him as guest stars are Lorenzo Pisoni (Gardner), Lee Tergesen (Cray Fielder), Jacob Alexander (Tom), Simon Belz (Kid), Irungu Mutu (Taxi Driver), Antonio Edwards Suarez (Sedan Driver), Leopold Manswell (Punk Boxer) and Bianca Amato (Brenda Resor).

Matthew Del Negro “Teen Wolf” alum Matthew Del Negro is guest-starring in Season 5, Episode 1 of “Elementary.” Pictured: Del Negro arrives at the Premiere of New Line Cinema And Metro-Goldwyn-Mayer's “'Hot Pursuit” at TCL Chinese Theatre on April 30, 2015 in Hollywood, Calif. Photo: Getty Images/Frazer Harrison

Del Negro’s Rafael McCall is the father of “Teen Wolf’s” main character Scott McCall (Tyler Posey), and since MTV confirmed that the series is ending after its upcoming Season 6, a lot of fans have began to speculate that Del Negro may be returning to the show to conclude his character’s story arc with Scott.

As “Teen Wolf” fans know, Rafael still doesn’t know that his son is a werewolf, so Scott might reveal his supernatural identity to his dad if he returns from San Francisco in the final installment of the series.

While it’s unclear whether or not Del Negro is indeed returning for Season 6, executive producer Jeff Davis previously teased to Teen Wolf News that “there will be another returning character or two” next installment.

“Elementary” Season 5 premieres on Sunday, Oct. 2 at 10 p.m. on CBS, while “Teen Wolf” Season 6 premiere airs on Tuesday, Nov. 15 on MTV.