The three players are key for The Bees and Downes wants to secure their futures ahead of the summer.
All of them are out of contract in the summer, but Downes has revealed that talks to keep them are now ongoing.
"I definitely want to extend the deals of key players, such as Ibrahima Sonko, Leo Roget and Kevin O'Connor (pictured)," said Downes.
"I want to take up Sonko's one-year option and put Roget under contract.
"I also want to keep O'Connor and contract talks with him are at an advanced stage."
