Dolphins head of performance Jeremy Hickmans told AAP second-rower Felise Kaufusi (grade two hamstring) was on track for a round 10 or 11 return.
Fullback Hamiso Tabuai-Fidow, also recovering from a grade two hamstring injury, should be back before the Queensland team play NSW in the State of Origin opener on June 5.
Maroons prop Flegler (shoulder) has not played since the round-five win over Wests Tigers.
"Flegs had some nerve damage. It sounds dramatic, but essentially it is like a burner to his shoulder, but a bad burner," Hickmans told AAP.
"We just have to take time to get his strength back. It is a little bit of a day-by-day or week-by-week proposition. It could come good straight away or take a bit longer, but it's going in the right direction.
"We will slowly reintroduce him to skills and keep working on his strength in the gym, which is getting better and better."
England international Farnworth suffered a grade-three AC joint sprain against the Tigers.
"Herbie is a bit like Flegs," Hickmans said.
"With him at the moment it is about settling it down, getting his strength back and slowly seeing what he can cope with. We did a little bit of contact in a looser sense on Tuesday and he is still a bit sore.
"We will introduce him to skills and see how he is feeling because essentially now it is not about risk of further injury. It is a pain management thing.
"We don't want to be jabbing him (with needles) for the rest of the year. An AC joint is one where you can do, but that can cause further problems. We have got the boys who can do the job in the (centres) in the meantime, so let's not rush him."
Hickmans said Tongan international Kaufusi, another casualty against Wests, was "going well" in recovery.
"In the next couple of weeks we should have an idea of where he will be. He could be back next week, but we are probably looking at round 10 or 11," he said.
Dolphins forwards Felise Kaufusi (second left) and Thomas Flegler (second right) are out injured. (Darren England/AAP PHOTOS)
Maroons star Tabuai-Fidow, injured in round six against Brisbane, is further away from a return.
"The challenge with Hammer is him, because he is so fast and explosive," Hickmans said.
"Getting him to that final (stage of recovery) is where we have to be careful with him. He was a grade two, but (the strain was) in a better place than Fus. His was more of a standard strain, whereas Fus was more tendon related.
"I imagine, and I touch wood when I say this, that Hammer will be back before Origin, but it's just a matter of when.
"All four are all on track. Two - Herbie and Flegs - are a little bit open-ended. Fus is getting closer and Hammer is ticking along."
8°C