'Arrow' Casts Charlie Barnett as John Diggle Jr. for Final Season

Meredith Jacobs
Courtesy of WBTV

John Diggle's (David Ramsey) sons are going to face off — on-screen — in the final season.

At Arrow's San Diego Comic-Con 2019 panel, it was announced that Charlie Barnett (Russian Doll) has joined the cast as a series regular. He'll be playing the adult John Diggle, Jr., known as J.J., Diggle and Lyla's (Audrey Marie Anderson) son. (If you'll recall, they had a daughter, baby Sara, until Barry created Flashpoint over on The Flash.)

So far, we've only seen J.J. as a kid, but the Season 7 flashforwards revealed he becomes the leader of the Deathstroke Gang and he and his adopted brother, Connor (Joseph David-Jones), are estranged. When we meet him in the future, he faces off against Mia (Katherine McNamara) and Connor.

Barnett joins previously announced new series regulars McNamara, David-Jones, and Ben Lewis, who plays William Clayton in the flashforwards.

Oliver Queen (Stephen Amell) and Team Arrow will be facing a "crisis" unlike anything they've faced before after the reappearance of The Monitor (LaMonica Garrett) at the end of the Season 7 finale.

'Arrow' Unveils First Final Season Trailer at Comic-Con 2019 Panel (VIDEO)

'Arrow' Unveils First Final Season Trailer at Comic-Con 2019 Panel (VIDEO)

Look back on Oliver’s journey and get a sneak peek of Season 8, including Tommy and Chase's returns!

Arrow, Eighth and Final Season Premiere, Tuesday, October 15, 9/8c, The CW