On the ABC cop drama, Luke (Johnson) cheated on his fiancée (Missy Peregrym) with his ex-girlfriend.
"He's at rock bottom," Johnson told TV Line. "Things aren't pretty for [Luke] right now. We'll have to wait and see if he's able to pick himself up and… redeem himself to a degree."
The actor added that "there is hope" for a reconciliation between Luke and Andy in the future.
"That ship hasn't sailed by any means," he insisted "There's definitely still a lot of love there. [But I don't think] that they're going to get back together right away. How could you? It wouldn't look good on her."
Former Smallville star Johnson also admitted that he had enjoyed playing out the infidelity storyline.
"We saw a side [of Luke] that wasn't as composed," he explained. "[A side that] wasn't as put together [and] that was a little compromised."
The second season of Rookie Blue continues on Thursdays at 10/9c on ABC.
> Rookie Blue season three renewal confirmed by ABC
Watch a promo for tonight's episode of Rookie Blue below: