The Northampton Saints hooker has not played since the final match of this year's Six Nations - on March 17 against Ireland - after being diagnosed with the third significant concussion of his career.
The New Zealand-born forward announced last month that he would be taking an extended break from rugby, ruling him out of England's summer tour of South Africa.
The 32-year-old is hopeful of returning to action for pre-season training with Saints but there are suggestions Hartley could be forced to call it quits as a result of the head injury.
Jones admits he is unsure what the future holds for Hartley and says it is possible he could have played his last game for England.
When asked about Hartley returning, Jones said: "You never know - nature decides when the player can come back. He just needs to wait and see.
"If he's right to play, he'll play. He'll come back with intent and dedication, and he's got to fight to get his place back in the England side.
"If he doesn't come back, he'll be remembered as the most successful captain England's ever had. Look at his winning percentage, it's higher than any other Test captain.
"It's extraordinary what he's done for this country and it's extraordinary the criticism he attracts."