Melbourne Heart have labeled tonight's clash with Sydney FC as a must-win 'final'.

The newest A-League club have gradually slipped down the table over the past few weeks with just one win and one draw from their last eight matches and feel that every game from now on is similar to a do-or-die final starting with the Sky Blues at the Sydney Football Stadium tonight.

Coach John van 't Schip stressed the importance of putting in a good performance, especially after they defeated Adelaide United, who had won seven in a row at the venue, at Hindmarsh Stadium last weekend.

"The most important thing is the mental (strength)," van 't Schip said yesterday.

"Every game we play is like a final and if we want to keep in the race we have to know that and be prepared for that. (Sydney) will fight for their last chance, as well, and we have to get a result if we want to really keep the pressure on.

"We know every opponent has a reason to perform well, but we have to look at our own reasons and that should be enough.

"With the win (over Adelaide) and the confidence we've got from the last game we can take that with us and have a good performance again."