If you thought Dallas's "Who Shot J.R.?" saga was shrouded in secrecy, consider the beefed-up security around Mark-Paul Gosselaar's debut on NYPD Blue. Even the Saved by the Bell cutie himself claims ignorance of most of the details, including his own character's name!

"I'll appear on the first episode [of the season] as an anti-crime officer until I get my detective shield, but that's about all I know," Gosselaar tells TV Guide Online. Of course, he'll be just one of many changes on the Emmy Award-winning drama series as it kicks off its eighth season this fall. Rick Schroeder's Danny Sorenson will be a distant memory, as will Kim Delaney's Diane Russell — the actress is off to star in NYPD Blue boss Steven Bochco's newest venture, Philly. Plus, accommodating her new series means that yet another timeslot switch (from Tuesdays to Wednesdays at 10 pm/ET) will pit Andy Sipowicz against Law &#38 Order's Lennie Briscoe.

"I don't think Steven or the cast are happy [about the move]," Gosselaar says candidly. "Our ratings are going to go down and so will Law &#038 Order's. Philly needs a good timeslot, but the network could've figured something better out. Steven let us know that he was not sabotaging one show for the other, though."

The actor says he's spoken to predecessor Schroeder in the past, but never about swapping police badges. "Years ago, Rick had a project he wanted to do and asked if I'd want to be a part [of it]," recalls Gosselaar. "The funny thing is that we have mutual friends, but we've never sat down and met face-to-face."

A nostalgic Gosselaar jokes that his Bell alter ego, Zack, "most likely has a wife and six kids" by now — a picture he hints is far tamer than the cheeky introduction he'll get on Blue. "They're going to hammer me," laughs the actor, referring to the series' penchant for showcasing its stars', ahem, assets. "I'm going to have to tan nude now. The pictures will probably wind up on the front of some tabloid that reads: 'Doing it all for NYPD Blue!'"