"I met him once. Ironically, he kissed my wife [Rebecca Romijn] in a commercial," O'Connell tells TVGuide.com. Belushi adds, "It was a fantasy sequence where she was coming in to buy a car and I had a fantasy where we kiss."
"So when I first met him, I had a little bit of a bone to pick with him because my wife soon caught mono after that," O'Connell jokes.
The exchange may seem like a bad first impression, but this ribbing is a perfect example of the pair's central on-screen friendship.
"Our show really centers on this kind of 'bromance' between those two guys," executive producer Greg Walker says. "Very few shows explore male friendship and this show does it openly and with a lot of fun. They give each other a hard time, they ride each other. It's a real relationship."
Premiering Wednesday at 10/9c on CBS, the show stars Belushi and O'Connell as two defense attorneys working hard and playing hard in Las Vegas. Based on two real lawyers, The Defenders was initially pitched as a reality series before CBS decided to turn it into a scripted drama.
When it came time to cast the show, the network set its sights on Belushi after having pursued the actor for several years. "Then the question became who do you match with Jim? Who can you make his partner in crime and partner in business and friend," executive producer Kevin Kennedy says. "Jerry came and we instinctively thought they would be really good together."
Kennedy says the two demonstrated immediate chemistry, thanks to the time they spent getting to know each other beforehand.
"I knew we had two great actors, but I didn't know if our show was going to work until I saw the first day between Jerry and Jim," executive producer Niels Mueller said. "From that point forward, I said this show is going to go."
Producers are hoping this slightly lighter take on a legal drama will help The Defenders make its case in a competitive timeslot when it airs opposite ABC's The Whole Truth and Law and Order: Los Angeles on NBC.
"Only through the casting of Jim and Jerry are we able to shift tones, where we have the heartfelt stories and then be able to shift gears and go into comedy," Mueller says. "They're great at the big moments, they're great at the little moments, and their chemistry is really what makes the show."
In the end, The Defenders is a legal drama, but producers know what happens outside of the courtroom and between their two leading men may make the biggest difference.
"It will be a procedural show, but the heart of it will be these two guys and how they deal with these procedurals," Kennedy says. "We could try to out-procedural all the other procedurals and out-law all the other law shows. Not that we won't try, but we have what we think the others don't — which is Jim and Jerry, the comic heart of the show."