The Blues skipper knows victory for the Irish will send Giovanni Trapattoni's side back to the top of Group Eight above world champions Italy, while even a point would be a welcome step towards South Africa next year.
Third-placed Bulgaria, by contrast, are in desperate need of a success to keep their hopes of qualification alive, as bullish back-to-form City striker Boji admitted earlier this week on mcfc.co.uk.
Dunney has already put his fellow Irish defenders straight about Bojinov's predatory powers now that the former Fiorentina star has shaken off his injury-ravaged season at the City of Manchester Stadium.
He admitted: "It's the last game of the season for us and probably one of the biggest we've ever had - a game where we can go back to the top of the group and put ourselves in a good position to qualify.
"I think Bulgaria will be really keen to try to win the game and will come at us - we just have to be sensible and play similarly to how we did against Italy ... be patient, take our time, and hopefully get a break and grab a goal.
"But the onus is on Bulgaria to win the game - if they don't, then it's us in pole position." The Republic were held 1-1 by Bulgaria at Croke Park in March before securing a memorable draw in Italy a few days later.
Left-back Ryan McGivern, a highly-rated Academy graduate yet to start a senior match for City, faces world champions Italy in Pisa for Northern Ireland.