The young Eels were stood down from round one following an early morning shooting incident at Kings Cross earlier this month, Hagan naming local juniors Taulima Tautai and Brendan Oake plus 2003 premiership winner Joe Galuvao in their place for Saturday's clash with the Bulldogs at ANZ Stadium.
Hagan confirmed the troubled trio would have been "certain" selections for the opening round game, but now had to earn their spots back and could be left out in round two if this week's side aims up against the Dogs.
"At this stage we'd like to think (Hayne) will be back for round two, but we'll re-assess that and Junior Paulo and Weller Hauraki at that time as well," said Hagan.
"Jarryd, Junior and Weller would have all been in the 17 this week for certain.
"I guess that's the beauty of this game, if you give someone else an opportunity and they make the most of it and play well enough on Saturday, then we have to re-assess for week two and week three."
Another troubled Eel, halfback Tim Smith, is likely to join the trio on the sidelines this week, but Hagan insists the week off is not related to Smith's weekend drinking session.
Hagan has no issue with Smith being drunk in front of club sponsors just three months after leaving a rehabilitation clinic, but says the 23-year-old needs to ease his way back from a shoulder reconstruction and will do so with Wentworthville in the NSW Cup.
"If medically they're happy for him to play and conditioning staff think he can get through the game he may play this week," Hagan said of Smith.
"If we're not sure we'll leave it another week and he'll come back that way at that time.
"It's a matter for him to get through some football and get some confidence, coming back from a reconstruction is a major injury."
Despite missing six first grade regulars for the clash with the Dogs, Hagan is optimistic his team can start making headlines for the right reasons on Saturday.
Nathan Hindmarsh will play his first game since knee surgery, while Galuvao has a "point to prove" after two bitter seasons with South Sydney.
"I'm excited about the fact we've got some quality players starting this weekend and I think we'll get better as the next few weeks unfold," he said.
"We have got some of the senior players who I still think have their best football in front of them."
Bulldogs coach Steve Folkes, who could easily sympathise with Hagan's tumultuous week having dealt with his own off-field dramas at Belmore, said it's about time football became the talking point in league.
"Everyone just wants the football to start and the players certainly just want to get out there and play," said Folkes.
"(Parramatta) had a fantastic season last year and just fell short at the last hurdle. They will be very strong this year and we aim to compete with them on Saturday.
"We want to see how we're going ... I'm confident we'll be more competitive than perhaps some people might think."