But he is determined to pile pressure on the Hoops, who have lost three of their last four games.
Jefferies said: "Celtic don't often lose back-to-back and there are two ways it can go.
"They might feel under more pressure, which is why we've got to get in about them, or losing at home could equally make them all the more determined.
"We can't worry about what they might do because it's what we do that counts for me.
"The good thing is that we're going into the game on the back of a great result against the team which has just beaten them.
"If we beat Hearts and they beat Celtic then we should be champions but, unfortunately, it doesn't work like that.
"We've competed well in our last few games against them and it took a wonder strike for them to win the championship in their last visit to our place after we'd matched them all the way.
"You've got to work hard, concentrate and take your chances when they come along when you play Celtic because they have better players than we do, but you can make up for that with organisation and determination."
Killie managed to hold the Clydesdale Bank Premier League champions to a goalless draw on the opening weekend of the season as the Hoops unfurled the league flag, and Jefferies knows his side will need a similar performance if they are to take anything again.
He said: "In that game we lost James Fowler early on and then Garry Hay at the start of the second half - two of our most experienced and consistent players.
"Our midfield that day was Steven Naismith, Jamie Hamill, Rhian Dodds and Willie Gibson but we managed to get a great result.
"Celtic had a lot of chances but Simon Ford had a great chance with a header. Gordon Strachan was very gracious afterwards and said we'd played well, deserved our break, but we've got to do that again."