The 33-year-old half back was handed a two-year drugs ban in 2017 after testing positive for use of cocaine – a suspension which will expire on July 14.
Chase trained for the first time with his new team mates on Tuesday night, two months out from his potential return date.
And he is delighted to be back in the game.
Chase said: “It feels good to be back.
“I’m really looking forward to getting involved and helping the lads at the business end of the season.
“I’m excited as I’ve had a long time out. Now that it’s not too far away I’m working hard to get my fitness levels as high as possible.
“The training will help me to get back up to speed.
“I want to try and get ready for July and get to know the boys as well.”
The signing will deliver a considerable boost to the Dons in their chase for promotion this season with Chase bringing top flight quality to the side.
Chase broke through at Castleford in Super League in 2009, earning eight England caps between 2011 and 2013.
He also won the Man of Steel Award in 2011.
Chase went on to feature for Salford, Leigh and Widnes after leaving Castleford in 2014. He had signed a permanent deal with Widnes when he was handed his ban, resulting his immediate sacking.
He has reportedly been working on his fitness over the last few months to ensure he would be ready to hit the ground running with the Dons, starting this week.
Dons chief executive Carl Hall is understood to have played a major role in bringing Chase to the club and is pleased to have got the deal done.
“We’re delighted to be able to bring a player of Rangi’s quality to the club,” Hall said.