Closer in tone to “Boston Legal” than the eponymous 1960s series starring E.G. Marhsall, “The Defenders” cries out for no-holds-barred, pay-TV treatment. Lacking that, “CSI” producer Carol Mendelsohn’s return to Sin City — by focusing on cut-rate defense attorneys in Las Vegas — is breezy but lacks much of a payoff, with the show’s viability likely to be determined almost entirely by one’s tolerance of Jim Belushi. It’s a lighter approach to the network’s procedural formula, to be sure, but based on the preliminary evidence, there are few grounds to deny a motion to dismiss.

Belushi and the well-traveled Jerry O’Connell play Nick and Pete, respectively, two zealous advocates whose client roster includes the various ne’er-do-wells, dreamers and losers who populate Vegas. Joining them in this venture is a wide-eyed new associate, Lisa (“Friday Night Lights’?” Jurnee Smollett), who has a little trouble adjusting to the duo’s win-at-all-costs tactics.

Nick is still harboring wounded feelings about his estranged wife (to the point of surveilling her), while Pete is a classic ladies man. They’re an unlikely team, but the interplay between the two of them is colorful enough — albeit mostly an excuse to get into courtroom drama leavened with humor.

It’s there, actually, where “Defenders” feels off-kilter, inasmuch as these are the kind of guys who would find themselves embroiled with low-lifes and scumbags in the pettiest, bottom-of-the-barrel cases. So when Pete draws a murder case in the premiere, one is reminded that CBS development executives’ hands start quivering whenever a script strays too far from a chalk outline.

Granted, “The Good Wife” turned out to be a rather pleasant surprise for the Eye network, but this latest legal franchise appears to harbor no such ambitions — and the gambling, booze and sexual debauchery associated with the town is inevitably going to be rather tepid and implied, even in a 10 p.m. timeslot. The show would be more defensible, oddly, if its characters could be a trifle sleazier — more like Bob Odenkirk’s amoral attorney in “Breaking Bad,” who frankly deserves his own show.

While “The Defenders” tries to position its protagonists as plucky underdogs, they’re pretty evenly matched in the Wednesday-night scheduling game opposite two other new series devoted to crime and punishment: “The Whole Truth” and “Law & Order: Los Angeles.”

Of course, CBS has overcome long odds with familiar-sounding concepts in the past, but in this case, don’t bet on it. Because sometimes, what happens in Vegas really should stay in Vegas.

The Defenders

CBS, Wed. Sept. 22, 10 p.m.

  • Production: Filmed in Los Angeles by CBS Television Studios. Executive producers, Carol Mendelsohn, Greg Walker, Kevin Kennedy, Niels Mueller, Davis Guggenheim, Joe Gantz, Harry Gantz; director, Guggenheim; writers, Kennedy, Mueller;
  • Crew: camera, Alan Caso; production designer, Bill Eigenbrodt; editors, Augie Hess, Farrel Levy, Mark Manos; casting, Felicia Fasano. 60 MIN.
  • Cast: Nick Morelli - Jim Belushi Pete Kaczmarek - Jerry O'Connell Lisa Tyler - Jurnee Smollett Sophie - Tanya Fischer
  • Music By: