In the end, it was try-scoring highs that convinced Grace to keep going.
"It's a bit of an addiction because the feeling of playing and scoring is something that you want to keep experiencing again and again," said the wing.
"One day I will be too old to even think about doing it again, so that's why I am giving it everything to come back.
"I am confident I will get back to my best. I have rehabbed with some of the best in the world and know what I need to do and where I need to get myself."
Grace is a realist. His medical record adds to the challenge, but he aims to prove he is worth a shot, be that in league or union.
"I just want to get to a point where I feel strong and confident before I even start thinking of talking to anyone," said Grace, who works with Sale's staff three times a week along with his own gym work.
"I don't want to go to a club when I am not fit. I want to be able to hit the ground running, or at least be ready to do a pre-season.
"One of the reasons that I said I was going to quit straight after the injury was that I don't want to let anybody down.
"If someone puts the time, effort and money into you it is horrible when you don't deliver what is expected.
"I feel that I have let clubs down because I have been willing to give 100% for them but physically haven't been able to."