"I don't feel ready to retire so this is clearly a sad time for me as I feel I have more to give," said Sanderson. "It is something that is still sinking in and it will take time for me to get used to the fact I won't be playing a game that has given me so much and has been so more than just a job over the last two decades.
"I have to look back at my career and look at all the wonderful memories. How privileged I have been to play the sport for so long and for some fantastic rugby clubs.
"I want to say thank you to all the people that have helped me along the way, in particular Worcester Warriors and all the fans for their support and the staff and players I have worked with. Ultimately this is where my rugby heart will remain.
"I will miss the environment and miss playing rugby, but I plan to keep a close relationship with Warriors.
"My time at Sixways has been incredibly special. When I came here Cecil Duckworth and the people involved at the time told me about the future and I bought into that dream. My biggest regret is that I cannot follow that dream to the end, but I very much look forward to now watching the continuation of that journey from the sidelines."