Betty Driver, who had played the part since 1969, passed away in October at the age of 91. She is yet to be written out on screen.
According to the Manchester Evening News, Roberts said that old faces from Betty's 42-year stay in Weatherfield will reappear for her April send-off.
Roberts teased: "I think we've come up with a fitting exit for her. It'll be shown in the spring. It's important we get that right because she was so loved by the fans and by all of us who work on Coronation Street.
"But it will mainly be about her and saying goodbye to her with the right amount of respect and the right tone."
There had earlier this week been a newspaper report suggesting that no former characters would be brought back for the special episode.
Jean Alexander (Hilda Ogden), Julie Goodyear and Roy Barraclough (Bet and Alec Gilroy), Sarah Lancashire (Raquel Watts) and Cheryl Murray (Suzie Birchall) have all been tipped to return.
Goodyear, who was on the Street with Driver for 25 years, has already signalled her intention to make a one-off appearance.
Producer Phil Collinson recently revealed that viewers will discover a long-held secret by the much-loved barmaid.
> Coronation Street stars pay tribute to Betty Driver
> Coronation Street's Betty Driver 1920-2011 - Obituary
Browse through a gallery of Betty Driver's life in pictures below: