‘GREY’S Anatomy” fans won’t have to wait long for last season’s cliffhangers to be resolved.

“Put it this way: It’s worth tuning in early,” says “Grey’s” executive producer Peter Horton.

“There are so many balls up in the air from the end of last year, and they’re not insignificant. And because the stakes are significant we’ve got to play it out rather quickly.”

Among those unresolved issues from last season’s three-hour finale: Will Dr. Preston Burke (Isaiah Washington) recover his surgical skills after being shot? What will happen to Izzie (Katherine Heigl), who quit the medical program in disgust after the death of her boyfriend, Denny?

Who will ever-fickle Meredith (Ellen Pompeo) choose: Derek (Patrick Dempsey) or the vet (Chris O’Donnell)?

“We can’t spend a whole lot of time on whether Burke will recover or whether Meredith is going to choose Derek over the vet,” Horton says.

“Of course we’ll play out the choices made, and their ramifications. Everything will obviously have resonance . . . but the suspense can’t last that long.”

“Grey’s” kicks off its new season tomorrow on its new day in its new timeslot (9 p.m.) – up against perennial ratings-grabber “CSI” on CBS.

“It’s always a scary moment when you’ve got a show that’s actually working . . . and when we first heard the rumblings [of moving the show], the initial reaction was one of trepidation, like ‘If it ain’t broke, don’t fix it,’ ” Horton says.

“But the truth of the matter is, every strategic step [ABC entertainment chief] Stephen McPherson has made has been quite extraordinary . . . like deciding to give us the post-Super Bowl slot [last season] . . . and that ended up increasing our viewership by 2 million a week.”

Horton also has a rooting interest in ABC’s “Six Degrees,” since he was brought in as a consulting producer on the new series from “Lost“/”Alias” creator J.J. Abrams (it premieres tomorrow at 10 after “Grey’s”).

“J.J. is a friend of mine, and we always talked about trying to do something together,” he says.

” ‘Six Degrees’ was stumbling a bit and needed a bit of support . . . It’s a really bold show to put on a network, so I want it to succeed.”