Wales lock Jenkins to miss November Tests with 'horrible' injury lay-off
Jenkins, 21, led his country during last year's Six Nations before undergoing surgery on the issues before the start of this season.
The Exeter forward is likely to return in December for the second-round Champions Cup game with holder Toulouse.
Wales play Fiji, Australia and South Africa next month as they eye a first Test win since October 2023.
"It's been horrible," Jenkins told reporters.
"It's probably the first time I've had such a long time off.
"The game I'm aiming for is Toulouse at home. I think that's December 15.
"So unfortunately I'm missing the autumn, but I'll definitely be up and running by the Six Nations," he added.
Jenkins has been a rare positive during Warren Gatland's second tenure as Wales coach.
The lock captained the side in the absence of regular skippers Dewi Lake and Jac Morgan last year after making his Test bow in late 2022.
"It's probably the first time I've actually felt fresh in four years," Jenkins said.
"Making my Exeter debut when I was 18, and then my Wales debut at 19, it's the first time I've had a bit of time to recover.
"The jump from under-20s level to seniors is huge and I probably underestimated that," he added.