TORONTO — Actor James Pickens Jr. - a.k.a. "The Chief" on "Grey's Anatomy" - knows he's got to do something about the libidinous interns on the hit show.

"They're driving me crazy," Pickens says in an interview, adopting his character's familiar look of exasperation.

"I've got to put them on lockdown or do something. Hopefully, I'm going to start putting a rein on them."

The results of his efforts - however futile - will be on display when "Grey's Anatomy" begins its third season Thursday (8 p.m. ET on CTV, check local listings).

When audiences last saw the talented (and seemingly sex-crazed) medical team from Seattle Grace Hospital, things were typically overwrought.

Izzie (Katherine Heigl) had abruptly quit the internship program after the death of her fiance Denny (she'd previously breached numerous medical ethics trying to save his life).

Meredith (Ellen Pompeo) was facing the fallout of a spur-of-the-moment encounter with her former paramour, the married Dr. McDreamy (Patrick Dempsey).

And the career of ailing surgeon Preston Burke (Isaiah Washington) was in jeopardy - although his tumultuous relationship with hard-driving intern Cristina Yang (Sandra Oh) appeared to be on more solid ground.

Not exactly an average day at the office.

But while viewers might consider the romantic hijinks on "Grey's" to be somewhat far-fetched, Pickens, 51, said doctors tell him the show is right on the mark.

"Right after the first season ... I happened to be at a social gathering where there was a physician couple who were both pediatric surgeons. The first thing they picked up on was the sex," he said during a promotional swing through Toronto earlier this summer. "They said 'Yeah, the on-call room, that's always the place.' "

Much has changed for the cast of "Grey's" since the show made its debut as a mid-season replacement in March 2005.

Onetime teen actor Dempsey is once again a magazine heartthrob. And Ottawa-raised Sandra Oh has become a bona fide star, winning a Golden Globe for her portrayal of the ambitious Dr. Yang.

Pickens, whose previous TV credits include "Beverly Hills 90210," "Roseanne" and "The Practice," acknowledged that the show's staggering popularity has changed his everyday life.

"This thing has gone above and beyond what I believe anyone thought it would," he said.

"The downside of that - if there is one - is, you know, you come into 20 million households every night, now, walking down the street has a different flavour to it. Your privacy is not so private anymore. But it kind of goes with the territory."

To get away from the spotlight, Pickens turns to the unusual hobby of cattle roping.

"It's a great escape from the craziness of Hollywood," he said. "It's a nice therapy for me. Even when I don't rope, just getting my horse outside is a great way to collect myself and be out in nature."

Pickens couldn't reveal what's in store for "The Chief" during the upcoming season, saying only that he expects to see his character's history as an alcoholic explored further as well as his relationship with Meredith's mother Ellis Grey (Kate Burton).

Diahann Carroll will guest star as Burke's mother when the show has its season premiere Thursday - a new night for "Grey's Anatomy."

In the U.S., much has been made of the time-slot change, which will see "Grey's" face off against ratings juggernaut "CSI: Crime Scene Investigation."

In Canada, where both shows are seen on CTV, "CSI" will follow "Grey's."

As for whether the antics at Seattle Grace can maintain their hold on TV viewers, Pickens lauded the writers on the program, suggesting there are plenty of wild plot turns to come.

"We've only seen part of the onion peeled back. The residents technically still have three years left, which in TV time could be seven years," he said.

"There's a lot of story there."