After the relative disappointment at last year's Olympics in Rio, where he followed his London 2012 victory with a bronze medal, Rutherford returned to training in January and started well.
Since then, however, things have not gone quite to plan, as he explained at his season debut at the Great CityGames in Manchester on Friday.
Rutherford, who won with a jump of 8.18 metres, said: "I got into really good shape very quickly but because I'm getting older - 30 isn't young in track and field, especially when you've had as long a career as I've had - my body just doesn't respond in the same way, sadly.
"So I've had a problem with my left foot, which is a new injury and a bit of a bizarre as it just flares up for whatever reason.
"And I've herniated two discs in my back, which hasn't been ideal.
"I don't need surgery, thankfully, but I've not been able to walk properly both times when it's gone - I've just had to wait for it to settle down.
"I guess it's part and parcel of the sport and I've had a few good years without too many injuries - I think it's just going to be something I have to deal with."
This year's target is a successful defence of his title at the World Athletics Championships in London in August, before defending his Commonwealth and European crowns in 2018.
His injuries prevented him from jumping in competition until Friday, although he did briefly consider going to the European Indoor Championships in March - "I asked British Athletics the question but it was all very late in the day", he said.
But having returned from his usual training camp with coach Dan Pfaff in Arizona, Rutherford is now ready to build towards London 2017.
He said the plan, "as long as my body holds up", would be to test his fitness at a small event in Italy before really gauging his form at the Diamond League event in Stockholm on June 18.
"If there are any problems with my back, we'll have to go see whoever the specialist is for that and we'll go from there," said Rutherford, whose partner Susie Verrill is expecting their second son in July.
"But the beauty of this year is that I don't have to qualify for the Worlds because I'm the defending champion, so I can be a bit more relaxed."
