Ruddock admits there is no timescale over when the 25-year-old, who made a sensational return to form last season, could make a competitive comeback.
But he insists the wing is remaining positive and there could be encouraging news in the near future.
"Marcel's injury is ongoing but we are hoping that there is light at the end of the tunnel with his problem," said Ruddock.
"He has a blood flow difficulty into the hip and the initial prognosis was that he needed to take weight off it so we put him on crutches. We were hoping that would prevent blood flow but it hasn't really happened.
"There is a possibility that he will now be asked to take some medication to make that happen. The worst case scenario is that he will need an operation to drill the hip. That is the last thing on the checklist and hopefully it will not come to that, we are looking to see some improvement with that condition over the coming weeks.
"It is a serious condition and we have to make sure we manage it properly and give him every chance to recover from it and not force him. There is no timescale on him, the best case scenario is that we will see him towards the end of the season; the worst case is that we see him next season.
"But now I believe we are seeing some light, in terms of the next stages if treatment, even if it involves medication. We know that is just around the corner, and if the surgeon says he is the next step then that is what we will do."
Ruddock revealed the entire club had been rallying around Garvey and he would continue to receive the best possible long-term care to ensure his return to the wing.
"It is frustrating for him. It is for every player after they have had a good pre-season. They just want to get out there and play so it is tough for him," added Ruddock.
"His fellow professionals have been very supportive of him and the entire club have totally supported him.
"Marcel is in every day and he is a good, fine young man with a young family so he wants to get it right, as do we. We will give him all the support we can to get it right and not pressurise him into a return too soon."