Fans who tuned in last week to the fourth-season premiere of TNT’s Tuesday LAPD police drama “Southland” may have noticed that many of the players were the same, but the pairings have been shuffled a bit.

Former rookie cop Ben Sherman (Ben McKenzie) finally moved on from his training officer, John Cooper (Michael Cudlitz), and was teamed with former detective Sammy Bryant (Shawn Hatosy), who’s now back in uniform.

Cooper, having recovered from back surgery, has a new partner, Officer Jessica Tang (Lucy Liu). And Detective Lydia Adams (Regina King), who has had a string of partners, hopes she’s finally found a keeper in her latest sidekick, Detective Ruben Robinson (Dorian Missick), a former Marine and veteran of the war in Afghanistan.

As to whether he’s sad that executive producers Christopher Chulack and John Wells broke up one of TV’s top “bromances” when they separated Cooper and Sherman, Cudlitz says, “It’s good. It’s the way of things. It had to happen. He had to try his wings and do his own thing. It’s actually a cool transition for the show. All these relationships and these people that we think we know are doing different things in their lives and their careers, so it’s almost like a reset.”

“Obviously,” says McKenzie, “the John-Ben relationship has been probably the central relationship on the show. Quite frankly, you can’t be at all accurate if you’re going to keep the training officer and student thing going past probation. The probationary period was already getting really long – three years.”