Bartley is expected to be able to take part in pre-season training within the next couple of weeks.
Cherries physio Steve Hard told the club's official website: "It was finally determined that Marvin had bilateral osteitus pubis, which is basically inflammation around the pubic bone.
"It was on both sides, but most of the symptoms were on the right.
He had one side injected earlier this month and the other side injected last week. The symptoms have decreased and it will be a case of doing a few things with him in the coming week.
"He may miss the first few days of pre-season training as we need to be careful with him as he has been out for three months but, because the injections worked, we are optimistic that he should be involved after that."