Toe surgery and calf problems prevented Jenkins from playing any part in the RBS 6 Nations and the World Cup warm-up games, with his participation at the tournament under serious threat due to a lack of game time.
The 30-year-old loose head, who was a Test Lion in both 2005 and 2009, even feared his stellar career might be finished due to the nature of the injuries and setbacks in his recovery.
"There are always doubts in your head especially given the type of injury I had," said Jenkins.
"The surgery was in an area that's pretty vital for my position, namely my toe.
"It's a dark time when you are injured, but the medical staff around me kept me going and kept reassuring me it was going to be right.
"A key thing for me was that when I had the operation in January the talk was to get me right for the World Cup.
"The coaches and physios made clear the whole reason behind me having the surgery was to get me back to full strength for the World Cup.
"But even up to the squad selection I was worried I wasn't going to be involved so I was pleased they picked me.
"It was a frustrating summer, I did all the fitness, all the preparations and was ready to go. Then eight days before the first England game my calf went during an optional session, so the timing wasn't very good.
"And mentally, after doing all that training and then picking up a problem just before the games started, it was a big disappointment."
The whole of Wales will have breathed a sigh of relief when Jenkins pulled on the Welsh shirt once again, especially as fellow Lions front rower Matthew Rees is unavailable for the entire World Cup campaign due to a neck injury.
Paul James has done a decent job in Jenkins' absence but having the 77-cap veteran back in the fold is clearly a massive boost to head coach Warren Gatland and co.
And it's not just Gatland and the fans who will be feeling better for Jenkins' return. The man himself is delighted to be back and is now desperate for more.
"I'm just so happy to be out on the field again. I was bouncing on the bench ready to get on after 20 minutes against Samoa," added Jenkins.
"It's a great buzz and I'm still on a high, it's been a long road and I have to thank the Welsh medical staff.
"It was good the coaches showed faith in me by putting me on the bench. They could have left me out because the props have been going very well.
"I probably wouldn't have lasted long but it was nice to get back on the pitch and have a bit of game time. Hopefully I'll build on that now.
"You want to prove that you can get back to the level you played at when you were in the team before. I knew I wasn't going to be there straightaway against Samoa, but it's a stepping stone to where I want to be."