Greg Grunberg took to Twitter to confirm his casting on “The Flash.”

“I couldn’t be MORE excited! Hey @grantgust, I’m a BADASS!!!” Grunberg wrote on the social media site just a few hours after Mashable broke the news that he landed a recurring role on the Grant Gustin-led series.

Grunberg, who rose to fame for his role as Matt Parkman on NBC’s sci-fi series “Heroes,” also posted a behind-the-scenes photo with Keiynan Lonsdale, who plays Wally West/Kid Flash on the CW series.

According to Mashable, Grunberg will play Detective Patterson — a “gruff, stalwart” figure at Central City Police Department known for his relentless commitment to protecting the city from all the dangerous metahumans that threaten it. The 50-year-old actor is set to make his series debut in Season 3, episode 7, titled “Killer Frost,” which happens to be directed by his “Geeking Out” co-host Kevin Smith.

According to synopsis for the episode, Caitlin’s (Danielle Panabaker) inner Killer Frost is unleashed after she uses her powers to save Barry (Gustin). When her metahuman self completely takes over her consciousness, Caitlin goes on a rampage looking for Doctor Alchemy and ends up fighting Barry and Cisco (Carlos Valdes).

As seen in the trailer for the episode, Caitlin also kidnaps Julian (Tom Felton) who gets hurt by her icy metahuman powers.

“Your friend, she’s a meta. [But] not one of the friendly ones,” Julian tells Barry in the clip. When Barry seems to defend Caitlin from his fellow CSI, Julian furiously calls her a “bloody menace” and shows Barry the arm injury he gets from his recent encounter with her. Despite all the troubles that Caitlin brings, Barry refuses to fight her.

Also in the trailer, Caitlin blames Barry for her frosty transformation. “You keep messing with everyone’s lives,” Caitlin tells Barry. “You did this to me! You make me cold, Barry.”

“The Flash” Season 3, episode 7 airs on Tuesday, Nov. 22, at 8 p.m. on The CW.

Greg Grunberg “Heroes” alum Greg Grunberg shared how excited he is about his recurring role on CW’s “The Flash.” Pictured: Grunberg arrives at the premiere of “Star Wars: The Force Awakens” in Hollywood, California on Dec. 14, 2015. Photo: REUTERS/Kevork Djansezian