Sessegnon's future at the Stadium of Light has come under increasing speculation in recent weeks, with the Benin international coveted by Qatari side El Jaish.
Di Canio believes that a proven playmaker would make all the difference to his side's chances of a successful campaign, challenging owner Ellis Short to adjust his budget and make further additions before the transfer window closes.
The Italian told the Sunderland Echo: "I cannot criticise the club because they already spent money. But obviously if they can make more sacrifices it would be better for the club because we would be a better side, suffer less, finish better in the league and help the company.
"I know Ellis has no problem in terms of money but the club in general can be better. In my opinion, these are worthwhile investments in the long run, but we will see. We have a strategy to work with what we can do.
"We might be able to bring in only one player, in which case a central midfielder. If someone wants to sell Sessegnon, I won't criticise if they bring me a striker with quality and experience and a central midfield player, but not one brought in as cover, not a kid, I need a central midfielder with a background, good quality, physical presence and experience."