Andy Murray could return to the tour as early as next month, but admits there is also a real possibility he may need a further operation.
The Scot has not played since November because of a bruise on his pelvic bone.
The former world number one says the last few months have been "unbelievably complex, challenging and difficult".
Murray, 32, now believes his lack of progress is caused by a common side effect of the hip resurfacing operation he had in January 2019.
The three-time Grand Slam champion resumed practice and running a few days ago.
He says the next few weeks will determine whether he needs another operation, or will be able to return to the ATP Tour - potentially as soon as the Miami Open at the end of next month.
"I have not had lots of clarity as to what the issue actually is, because it is difficult to tell," Murray said.
"What I need to do just now is build up in these next couple of weeks to really test it. I will really test the hip out. Hopefully it responds fine.
"I should know by the end of next month whether I'm good to play or not with it. But I think I am now at a point where we're pretty sure as to what is going on."
'I want to keep playing - it's just whether I'm able to'
Murray was diagnosed with a mild bruise on his pelvic bone after beating Tallon Griekspoor of the Netherlands in Great Britain's opening tie of November's Davis Cup Finals in Madrid.
A month earlier, he had won the European Open in Antwerp to claim his first singles title since 2017.
But he continued to experience discomfort in the groin area into the new year, and now believes that was caused by bone growing in soft tissue around his new metal hip.
The medical term is heterotopic ossification, but it is difficult to be absolutely certain as a scan of a metal hip can be hard to interpret.
Murray hopes rest has allowed the condition to stabilise - and that he will now be in a position to resume his career.
But he accepts an operation to remove the growth may be necessary.
To further complicate matters, Murray has been told the bone could continue to grow for another few months. That means any operation is likely to be delayed, which in turn would almost certainly rule him out of Wimbledon and the defence of his Olympic singles title in Tokyo.
"The issue is if you try to remove that too early, while it is still active in the process of growing, it just grows straight back," he continued.
"If I have to have that removed because it is what is causing the problem, then that is a pain ... It's not that long an operation really in terms of the rehab and stuff. But it's just if I wasn't able to have it until May or whatever, with six to eight weeks' rehab, then that would mean missing that period."
The best case scenario, though, is to imagine Murray's name appearing in the draw for the Miami Open, which begins in Florida on 25 March.
"There's no reason not to, because I don't have an injury as such. It's just whether that settles with time and the body gets used to it, and whether you are able to manage it when playing.
"I would [then] play on clay, for sure. If physically I am fine and this responds well to the training again, there is no reason for me not to. In many ways, the clay should actually be better for a metal joint because it is softer impact-wise.
"I do want to keep playing. It's just whether I'm able to or not is the question. I want to play in the Slams again. That's what excites me and interests me. That is the thing that I have missed over these last few years.
"Missing the Australian Open for me this year was rough. At the end of last season I was actually starting to play pretty well, I was feeling good - and then this happened.
"From chatting about it, I feel it's [coming across as] really negative. The negative thing for me would be if something really bad was wrong with the prosthesis. But there hasn't been any problem with that at all.
"I might be playing in the next few weeks. That's what I hope, but over the last couple of years I have become quite pessimistic about time frames and stuff because of what has gone on, and what has been said to me."