FC Twente's serene progress at the top of the Eredivisie suffered a slight wobble this week when it emerged defender Ronnie Stam has rejected a new contract offer.

Twente wanted 25-year-old Stam to extend his current deal which expires at the end of the 2010-11 season but the right-back was not interested.

Club chairman Joop Munsterman said: "Since his arrival Ronnie has performed well and we were hoping to reward him."

Despite the snub, Stam will continue to remain a key figure for Steve McClaren's league leaders who host Vitesse Arnhem this weekend.

Twente are two points clear of PSV Eindhoven, who hold the only other unbeaten record in the top flight.

PSV also have a winnable home game when they meet Heracles at the Philips Stadion.

Third-placed Ajax take on Heerenveen in Amsterdam with striker Mitchell Donald expressing his delight at the impact made by new coach Martin Jol.

Donald told the club's official website: "He is a top coach.

"He understands the squad. Sometimes you have moments where you think 'the intensity is too high' and he suddenly drops it.

"And then you might think 'it would be nice if he turned to me' and then he does just that."

The Amsterdammers are likely to have Marko Pantelic in their ranks. The Serbia striker injured a hamstring in the 1-0 defeat to Twente and missed his country's friendly matches against Northern Ireland and South Korea.

He has resumed training, however, and ought to be fit for this weekend.

Fourth meets fifth in Rotterdam with Feyenoord playing host to FC Utrecht.

The hosts could be without Denmark striker Jon Dahl Tomasson, who is struggling with a thigh injury.

New coach Wiljan Vloet takes charge of NEC Nijmegen for the first time when they go to NAC Breda.

Vloet, who moved to NEC after working in PSV's youth system, said on his introduction: "I know what ambitions NEC have and which way it wants to go.

"But in the short term we need to make the fans proud. That won't be easy but we have to take a number of steps."

It is a tricky start for Vloet as his second-bottom side take on a NAC outfit which is riding high in sixth.

AZ Alkmaar midfielder Rasmus Elm has stated his desire to stay at the defending champions despite having to sit on the bench in recent games.

The young Swede said: "I'm enjoying myself in Alkmaar.

"I can understand it that if the team is on a good run, the coach does not want to change the side."

AZ go to Roda JC on Saturday.

Elsewhere this weekend, rock-bottom side RKC Waalwijk take on FC Groningen on Saturday while, on Sunday, Sparta Rotterdam go to VVV-Venlo and Willem II meet ADO Den Haag.