The 20-year-old broke into the first team in 2015-16 but featured just twice before suffering an anterior cruciate knee ligament injury during a training session last July.
Watkin has now completed his rehabilitation and is training with the rest of the squad as they put in the hard work before the start of the new campaign in September.
The centre insists he is in top condition and desperate to get some competitive action after over a year feeling isolated.
Watkin said: "It's tough mentally when you're injured. You feel isolated and my injury was such a bad one it meant there were a lot of ups and downs.
"I'm fully fit now. It's been great to get back working with the rest of the team. I was so used to playing week in, week out, so to go from that to not playing for nearly two years was a big shock.
"Now I just want to get out there."