Vladimir Vermezovic's side currently trail the Buccaneers and second-placed Ajax Cape Town by six points, with Mamelodi Sundowns in third - four points ahead.
A victory in their game in hand would therefore give Chiefs a real opportunity to win their first championship since 2005 but Erasmus is determined that the reigning PSL title-holders will not give up without a fight.
"Chiefs know they have to beat us to stay in the title race and that should give us an advantage," he told Football365.co.za.
"All of the pressure is on them to get the result and we can use that to help win the match. They know they will probably have to win all their remaining matches to stand a chance but we also need the points if we are going to finish in the top eight."
Chiefs have drawn five matches in succession since Thulasizwe Mbuyane's last-gasp goal denied them victory in February's Soweto derby. And having played all four of the contenders in his first season back in South Africa after a stint at Dutch giants Feyenoord, Erasmus thinks Foppe de Haan's Ajax Cape Town are the most likely to win the league.
He said: "Without a doubt, Ajax are the best team I have faced this season but they lost some concentration to allow Sundowns to come back last week. I think they have a good mixture of old and young players that has served them well.
"Pirates are probably the favourites at the moment but if they slip up then I think Ajax are in a great position to take advantage."