The Aussie ace enjoyed a good season this year as he played his part in Parrys International Wolves reaching the play-offs.
He notched 189 points from his 22 appearances and has done enough to earn a place next season alongside youngsters Leon Flint and Drew Kemp.
“I’m pleased it’s all agreed for next season,” he said. “Wolves is a great club and I’m more than happy to stay there.
“I also want to try and make a success of meetings in Poland so it’s a big season for me.
“I know the way the team is shaping up and I like it, I think we can be competing for the play-offs again.”
Douglas was pleased with how his season worked out.
“It went well,” he added. “I think we were a good team and I’m generally pleased with how my form was, I could have done better in some meetings but generally I think I did pretty well.
“But I’m always looking to build on every season and I want to do more in 2022 for sure.”
Four signings are still to be revealed including a replacement for Rory Schlein, the skipper who has returned to Australia to start a new life in retirement.
Club bosses know the riders they want and more news is expected to follow in the next few days.
Club owner Chris Van Straaten will be at the stadium on Saturday week, December 11, for the sale of advance ticket books for 2022.
He will be on hand between 10am-2pm and believes many fans will take up the opportunity. Application forms are available to download from the club website.
Meanwhile, Premiership rivals Sheffield and Peterborough have unveiled their full teams.
Sheffield have signed former Wolves man Tobiasz Musielak and another ex-Wolf Kyle Howarth remains at Owlerton.
Peterborough include six of last year’s title winning side plus talented young Dane Ben Basso who replaces Bjarne Pedersen who, like Schlein, has retired.