There's still no word on when Chuck will debut on NBC.

But more casting news continues to trickle in about this beloved series. The latest involves a guest star even tougher than Stone Cold Steve Austin.

Fans can look forward to an appearance by Robert Patrick midway through the third season. The actor is best known for playing the T-1000 in Terminator 2. He popped up, as Colonel Merton Bell, on an episode of NCIS this year.

According to Entertainment Weekly, Patrick will portray Col. Keller on Chuck. The character is a mysterious figure from Casey’s past.

We can't wait for this show to return.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.