Like his ex-Blackburn team-mate El-Hadji Diouf, Frenchman Chimbonda is using Rovers as a shop window for a return to the Premier League.
He told the People: "The reason I am here is because only this team gave me my chance to play football again. This is a chance I jumped at.
"The Championship is really hard. There are so many teams who have come down from the Premier League who find it hard to get up again. It is a tough league."
Chimbonda, who admits he did not know much about Doncaster until six weeks ago, was keeping fit alone near his home in Loughton, Essex.
He added: "I hope to do well until January and we will see what happens.
"It is the dream of every player to play at the highest level, so if I play well and get the chance to go back in the Premier League then I will be very happy.
"I didn't feel I would not play again, but hour after hour went by and then the season started, the Premier League teams picked their squads, and I was not in the business any more.
"The way that football is now, I want to make sure I keep playing, do well for the team and if the team to do well that might help me step up."