The second-placed side host De Graafschap on Sunday afternoon and anything less than a win, coupled with three points for leaders PSV Eindhoven against Heracles Almelo, would mean Ajax have failed to clinch the title for the fourth season running.

Koster knows PSV's result is out of his hands but is adamant the race is not yet over, especially as his side face a team they beat 8-1 on the opening day of the season.

"Five points is a big gap but we can not exclude anything," said Koster. "It is still possible, although it will not be easy."

Gabri (hamstring), Gregory van der Wiel (knee), Erik Heijblok (shoulder) and Laurent Delorge (achilles) all miss out for Ajax, as does Bruno Silva, who is suspended.

Thomas Vermaelen and Dennis Rommedahl face late fitness tests.

De Graafschap coach Jan de Jonge is aware of the need to take points from the last three games to ensure Eredivisie survival.

The Superboeren are one place and a point above the last relegation play-off spot.

"It is now all about the points," said De Jonge. "Three points could be enough in the last games. But one is also a possibility. We will try to get a good result in Amsterdam.

"We want to leave there with a good feeling. The team believes we can stay in the Eredivisie."

De Jonge has no injury worries after Joost Volmer and Rogier Meijer returned to fitness but Purrel Frankel is suspended.