The 31-year-old came through Tigers’ youth ranks and made his debut for them in 2007.
He left his hometown club three years later and had spells with Hull FC, Warrington Wolves and Toronto Wolfpack before joining Trinity ahead of the 2020 season.
Arguably the most in-form loose-forward in Betfred Super League this year, he has been called into the England squad for Friday’s Test against Combined Nations All Stars.
“It’s been about 10 years since I last played at Castleford and since I was a young kid, I have always supported Cas,” Westerman said.
“My whole family around me support Cas so it will be good and it is something I am really looking forward to.”
Westerman added: “Cas has always been a big club in my eyes.
“From being a kid and supporting them to now, where they are up there with some quality players, it is really exciting.
“The standard is really high now and I just want to get there and play well for my hometown club next year.”
Westerman insisted he is grateful to Trinity for reviving his love of rugby league.
“I’m loving my time at Wakefield and I have the utmost respect for the club and the people in it,” he said.
“It has made me enjoy my rugby again and I have got a lot to thank Wakefield for. I get up every morning loving going to work.
“I have realised the little things you have to do away from the pitch to make you a better player.”
Westerman is no stranger to incoming Tigers coach Lee Radford, following their time together at Hull.
“I have worked with Lee Radford for a lot of years,” Westerman recalled.
“I get on well with him as a coach and as a person.
“I honestly that he will do a great job at Cas and he’ll have the fans on his side straight away.”
Radford is excited about Westerman’s return to the Jungle.
He said: “Joe is in very good form and he is in a good place in his life.
“He is at a point in his career that he has a couple of years to win something.
“In my opinion, he should have more international caps than he has, but for whatever reason that hasn’t happened.
“I honestly think, for a ball playing 13, there aren’t too many better in the competition at the minute.”