The Rookie has set itself apart from other policing shows and procedurals by prioritizing characters, rather than cases. As such, its main characters have developed much more than in other dramas. At this point, almost everyone on the ABC series has their own storyline, love interest, conflicts and goals, and the wide array of characters has continued to make the show better.

Season 4 of The Rookie continued that trend and did a lot of things right. The introduction of rookie officer Thorsen ensured that the series maintained its premise. Meanwhile, Harper and Nolan started relationships that pushed their characters into whole new directions. The most important development, though, was setting Nolan up as a training officer. With a lot of those story arcs still in progress, fans of The Rookie think they know what's coming in Season 5. Yet the series might be getting ready to do something unexpected.

RELATED: The Rookie's Niecy Nash Spinoff Could Be Too Political - and That's a Problem

Will John Nolan Be a Bad Training Officer?

The Rookie John Nolan sits in an LAPD classroom with other recruits

When The Rookie started, Officer John Nolan was the main character. He had moved cross-country to become an officer in the Los Angeles Police Department. Everything revolved around him and his character development, but as the other rookies around him became more important, Nolan faded into the background. Some fans even thought that he was the series' weakest link. However, that started to change in Season 4 when he applied to be a training officer. He even got a taste of training when he and his wannabe rookie got into a firefight in the Season 4 finale. Apparently, that trial run didn't scare him away because The Rookie is changing its premise to allow Nolan to become a full-on training officer in Season 5.

Fans expect that Nolan will be a stellar TO, but will he? Through four seasons, he's had a very laid-back and endearing personality, but that may not translate well to a TO position. In that role he will have to clearly take the lead and probably need to regularly reprimand his trainee. It will be interesting to see if he can find a balance between his personality and being a demanding teacher. If he's too soft, he'll be doing a disservice to his trainee, but if he's too domineering, it won't be good for his character or the people around him. Hopefully Nolan can have a mostly seamless transition into his new role; if not, he won't make it as a TO.

RELATED: Shows to Watch If You Like The Rookie

Can Chenford Really Be Permanent?

The Rookie's Finale Gave Chen and Bradford Fans a Chenford Kiss

Since the early days of The Rookie, fans have wanted Chenford. Officer Bradford was Officer Chen's TO over the first few seasons, but the romantic chemistry between them was obvious. Naturally, The Rookie has been slow and deliberate in bringing them together, but the end of Season 4 showed some promising signs. The two of them were preparing to go undercover as a couple, so they practiced their PDA, the sparks flew, and fans immediately started freaking out. It seems like there's only a matter of time before they wind up together -- however, the odds of Chenford working out long-term feel slim.

The two of them as a couple feels like something that would end a character arc, like Ziva and Tony DiNozzo on NCIS. Fans always wanted Tony and Ziva together, but it never happened until they were both offscreen. Similarly, Chen and Bradford feel like they're about to be a couple, but there's no way it will be sunshine and roses from here on out. The show's modus operandi has been short-term pairings that don't work out. And the series already has its successful couple in Angela and Wesley. Fans might riot if Chenford falls apart, but it would set up a different "will they, won't they" for the characters and be a good way to create drama for Season 5.

The Rookie Season 5 premieres Sept. 25 at 10:00 p.m. on ABC.