ER may be losing original castmembers Anthony Edwards and Eriq La Salle at the end of next season, but Goran Visnjic — who has played Dr. Luka Kovac since 1999 — insists that the top-rated medical drama will not flatline in their absence.

"Lots of people are going to stay on the show and [producers are] going to probably bring lots of new people in," the 28-year-old actor tells TV Guide Online. "So, it's going to be just the same."

Well, not quite. For starters, the defections will likely mean more screen time for Visnjic — not to mention more opportunities for the Croatian-born hunk to stumble over the complex medical jargon. "I have been on the show for two years already and [I've completed] lots of projects in English now, so it's not a concern anymore," he says of the tricky dialogue. "It used to be a big concern, but not anymore."

Visnjic wouldn't reveal what's in store for Luka next year, but considering how his perpetually troubled alter ego spent much of last season blaming himself for the death of his wife and kids, happier times must be ahead, right? "You can't change him overnight," he teases, cryptically. "[But] we're going to see him this year in definitely a different light."

In the meantime, ER fans can catch Visnjic as they've never seen him before in the just-released suspense thriller The Deep End, in which he stars as an evil blackmailer. "When you're playing a really bad guy, you don't know how to react in his skin," he recalls. "Because the only things that I did in my life that were illegal were parking tickets."

And despite the good buzz surrounding The Deep End, Visnjic has no desire to ditch his day job to pursue a big-screen career. As it is, ER is not unlike film work — as the thesp discovered while working on the show's 150th episode last season. "It was like shooting some huge big budget movie," he marvels. "Being on a show like this is definitely a great thing."