"It has been a long road back, and I have to thank Wales' medical and physiotherapy staff for doing great work with me," said Jenkins from their base in New Zealand as Warren Gatland's men prepare for their clash against Namibia.
"I am just so happy to be on the field again. I was bouncing on the bench, ready to get on after 20 minutes against Samoa.
"I probably wouldn't have lasted long, but it was just nice to get back on the pitch and have a bit of game-time. Hopefully, I will build on that now.
"There are always doubts in your head that you are right, especially given the type of operation I had. The surgery was on an area that is pretty vital for my position, namely my toe.
"It is 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."
After recovering from his toe problem in time for Wales' tough World Cup preparations, Jenkins then suffered a calf injury ahead of the opening tournament warm-up game against England.
"It was a frustrating summer," he added. "I did all the fitness, all the preparation and was ready to go. Then, eight days before the first England game my calf went during an optional session. The timing wasn't very good.
"But I picked myself up, and once you are out here (at the World Cup) then you know you are in the mix - you are part of it.
"The calf injury was just a random occurrence towards the end of a training session. It was a dark time because I had been out for so long with the toe and I had worked so hard to get fit.
"I guess a key thing 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.
"The calf problem set me back a bit, but at the back of my mind was the knowledge that they wanted me for the World Cup."