Coppinger was originally set to leave Doncaster,but has now agreed a two-year extension to dismiss any rumours of him departing South Yorkshire.
Tyson and Main have both agreed deals with Doncaster as replacements to Chros Brown and Billly Sharp.Dickov says the move was only possible due to James Husband's transfer to Middlesbrough.
"James' sale has generated transfer money and we've gotten Curtis Main in return.He has a lot of talent and potential about him,"says Dickov.
"Curtis has been looked down on a lot because of his record at Middlesbrough but he needs some game time to both mature and develop as a team player."
"Tyson has been at us since the Portugal trip and I'm glad to get him.He has an atheltic approach to the game and is a good example for Alex Peterson to follow along with that of Theo Robinson."