Rob Baxter, Exeter's director of rugby, said Friday it was still a "little bit fluid" when it came to a date for the 21-year-old second row's playing return, but that he would be unavailable for the English Premiership opener against Leicester on September 21st.
Wales begin their end-of-year international campaign with the visit of Fiji to Cardiff on November 10th.
Jenkins, a veteran of 19 Tests, captained his country in all five games of last season's woeful Six Nations campaign, with Wales finishing bottom of the table after suffering the embarrassment of a whitewash.
He was then unavailable to face South Africa in June, with hooker Dewi Lake taking over as skipper for that match and subsequent two-Test Australia tour.
"It is tough and frustrating for Dafydd," said Baxter. "He has had surgery on a knee issue sustained on the summer tour with Wales, then he's had a sore shoulder/rotator-cuff type of injury as well.
"Both the club and Wales feel now is the right time to have them both addressed."
Baxter added: "He is a young man who has played a lot of rugby for both Chiefs and Wales, so it is important that he gets them sorted properly now so that he has that extended period of rehab to get himself back fit and ready for what everyone knows is going to be a very good career."
Exeter will also be without England centre Henry Slade when the season starts, with the club announcing a fortnight ago that he had undergone shoulder surgery.
