Keeping a watch on TV

Seinfeld’s signing off won’t mean there’s nothing worth watching on Thursday nights

With the declining ratings for Friends and ER, the lack of any new breakout-hit sitcoms, and the announcement that this will be Seinfeld’s final season, NBC — for the first time in many years — is now officially vulnerable on Thursday nights. Thus, the introduction of two action-packed alternatives to the Peacock’s Must See TV lineup suddenly becomes all the more intriguing.

The first isn’t really a new show: New York Undercover (Fox, Thursdays, 9-10 p.m.) had served as solid counterprogramming to Seinfeld for three seasons before the network unexpectedly yanked it off the schedule last spring. Its replacement, the dour inner-city drama 413 Hope St., was an unlucky number with viewers, so NYU is back with a trio of new cast members and a funkier downtown location.

Last season’s cliffhanger killed off series regulars Jonathan LaPaglia and Michael DeLorenzo — neither’s a great loss. The fourth season picks up six months later, as surviving cops J.C. Williams (the eternally cool Malik Yoba) and Nina Moreno (Oz’s marvelous Lauren Velez) are assigned to an elite new crime-fighting unit.

Unfortunately, this means the underrated Patti D’Arbanville (who played the grumpy lieutenant at their old precinct) has left the show. Fortunately, she’s been replaced by Tommy Ford, long one of the strongest comic presences on Martin, who proves equally adept at drama as their no-holds-barred boss, Lieutenant Barker. NYU’s two other new stars, Marisa Ryan and Josh Hopkins (veterans of Major Dad and G.I. Jane, respectively), seem like little more than pretty faces so far.

NYU remains a well-crafted cop show distinguished by legit Manhattan locations, flashy visuals, cannily chosen music (Velez grieves for murdered husband DeLorenzo to Toni Braxton’s ”Un-Break My Heart”), and smart guest casting. Erik Todd Dellums shines in the season premiere, infusing his Muslim terrorist with the same kind of insinuating menace he brought to Homicide drug lord Luther Mahoney. Meanwhile, Jon Polito (another Homicide alum) steals the second episode as a scumbag strip-club proprietor who helps bring down a bloodthirsty modeling agent.

Like NYU, the new sci-fi serial Prey (ABC, Thursdays, 8-9 p.m.) benefits from sleek production values and an above-average cast. The show’s concept is Al Gore’s worst nightmare: Global warming has unleashed a new breed of evil creatures. They look just like humans (which saves money on makeup), but their DNA is different. And, oh, yeah, some of them happen to be serial killers.

Enter Debra Messing as Sloan Parker, a bio-anthropologist who stumbles upon this new species after one of them murders her mentor. Messing, always the weak comedic link on Ned and Stacey, seems better suited to a brainy-heroine part (her role was played in Prey’s never-aired original pilot by ex- Twin Peaks vixen Sherilyn Fenn, who would’ve been hard to swallow as a scientist). The reliable supporting cast includes Adam Storke (Prince Street) as a shady FBI agent, Frankie R. Faison (Do the Right Thing) as a world-weary cop, and Larry Drake (L.A. Law’s Benny) as Messing’s new supervisor.