Campbell, 30, has joined the Saints as a delisted free agent, signing a one-year contract.

The move comes after St Kilda failed to land Kangaroos tall Tristan Xerri during last month's trade period.

Campbell will support first-choice ruck duo Paddy Ryder and Rowan Marshall after Paul Hunter, Sam Alabakis and Shaun McKernan all departed.

"We're really pleased to have signed Tom for 2022," Saints list boss James Gallagher said.

"Stability in our ruck is extremely important for us, and we believe Tom will provide important depth, competitiveness and flexibility to allow us to maintain our structure next season.

"Tom is known for his professionalism and team-first approach and will no doubt be a great influence on our young and developing players."

Campbell has played 54 AFL games - 12 for North Melbourne and 42 for the Bulldogs - since being selected in the 2011 rookie draft.

He was delisted by the Kangaroos last month after playing nine games this year.

St Kilda are looking to bounce back in 2022 after tumbling down the ladder last season, finishing 10th with a 10-12 record.

Stengle was dumped by Adelaide in March following a string of off-field incidents.

The 22-year-old and then-teammate Brad Crouch were caught by police with an illicit substance in the Adelaide CBD last year, while Stengle was also charged with drink driving during his time at the Crows.

After being sacked by Adelaide earlier this year, the speedy forward produced a brilliant SANFL season with Woodville West Torrens Eagles to attract the interest of several AFL clubs.

Geelong decided to hand Stengle a two-year deal after receiving assurances from him that his off-field troubles were a thing of the past.

"It is rare to be able to pick up such a young player as a free agent, and we are thrilled that Tyson has decided to continue his career with Geelong," general manager of football Simon Lloyd said.

Australian Associated Press