Retiring NSW skipper Gallen and Hayne combined for the Blues drought-breaking series win in 2014.
"I think everyone would like to see him back," Gallen said. "He's a drawcard. I just spoke a minute ago about drawing kids to the game and he does that.
"He missed out there, it would have been a pretty good thing to go to the Olympic Games but it wasn't to be for him and certainly I'd love to see him back in the NRL."
NRL boss Todd Greenberg opened the door for Hayne's return after hearing he wouldn't be at the Rio Olympics.
""We have always made it very clear that we would love to see him back," Greenberg told Fairfax Media.
"I actually sat with Jarryd in round one at Pirtek Stadium this year and told him we would welcome him back. That has only strengthened on today's news.
"So, if and when Jarryd is prepared to make the decision on the next stage of his career, if he wants to have a discussion with us about the NRL, we are more than happy to have that discussion."
However Greenberg ruled out using the NRL's much-vaunted war chest to tempt Hayne back to the NRL, after the former Kangaroos representative posted on Facebook of his Olympic snub.
"I used all my experience as a professional athlete and have tried every day and in every way possible to make this team and make it better but unfortunately, time has been against me," Hayne wrote.
Kieran Foran's exit from the Eels would free up funds for Hayne to return to the Eels.