Kiefer Sutherland revealed that an older and angrier Jack Bauer is coming to "24: Live Another Day." Kiefer Sutherland believes that it may have been a "dangerous" choice to reboot "24" for season 9.

"I'm focused on these 12, and I'm nervous about it," Kiefer Sutherland admitted to TODAY, referring to the 12 episodes of "24: Live Another Day."

"We did eight seasons that we were all proud of, and so to open the can up again is potentially very dangerous."

Sutherland is currently filming season 9 of  "24" in London, but refused to give too much away about the plot.

"We're doing 12 episodes this year instead of 24," he told the Mirror.

"It's a terrorist threat. There are a couple of other changes.

"I can't go into it at length but some of the characters that are more familiar to the audience that are coming back, their relationships in these last four years have dynamically changed as well, so it will be very fresh because it feels very fresh to do it right now.

"At the root of it, he's [Jack] going to have a sh**ty day."

The 47-year-old actor admitted that Jack will be angrier - and older - in "24: Live Another Day."

Agent Jack Bauer, who Sutherland hasn't played since "24" ended with season 8 in 2010, might be "a little slower" as the years catch up with him.

"I have to kind of skip, hop before I can start to run, just so I don't snap a tendon," he joked.

"If it was at all possible to make Jack more angry or pissed off than he was before, that's what we're gonna try and do with the ninth season," Sutherland hinted, DigitalSpy.com reports.

Sutherland will be joined by fellow "24" veterans Mary Lynn Rajskub, Kim Raver and William Devane. New cast additions include Tamer Hassan, Stephen Fry, Yvonne Strahovski and Colin Salmon.

"24: Live Another Day" opens with a two-hour premiere on May 5 on Fox.