When Dearden injured his ankle, his return was always slated till Round 20-22. According to the NRL Physio (one of the best voices in Rugby League, check him out) it usually takes 8-10 weeks to recover from a Grade 3 Ankle Sydesmosis injury.
I expect to see him back next week.
I also wouldn't be surprised to see Shibasaki back this week. It will be interesting to see where he ends up playing, especially after Staggs enjoyed his best performance of the season on the right-hand side. Despite the criticism, I actually think Gehamat has a lot of what you want out of a modern centre. If he could just convert his chances I think the fans will see what the coaching staff at the Broncos see in him.