Coach Frank Rijkaard told a press conference at Holland's Hoenderloo training base that he was still assessing the situation on both players.

De Boer injured his groin in training on Tuesday and could be replaced on the right side of midfield by Marc Overmars should he not pull through.

Keeper van der Saar could be replaced by Liverpool's Sander Westerveld, who came in for the 3-2 victory over France in their final group D match on Wednesday.

The 29-year-old Juventus star injured his left leg in trying to save Michael Schonberg's 80th-minute penalty in the co-hosts 3-0 win over Denmark in Rotterdam last Friday.

Rijkaard said on van der Sar: "He's still training separately and has not joined the group yet. As far as selection against Yugoslavia I have no clue whether he will be available.

"We will take the situation as it comes from moment to moment. It's difficult to tell what will happen in a couple of days time."

On Ronald de Boer, Rijkaard said: "He is making good progress and has been treated extensively."

De Boer did train on his own, but only for an hour of a nearly two-hour session, including all 22 players, after warming up for 20 minutes with the main group.

Paul Bosvelt has a slight chance of keeping Michael Reiziger out of the right back position after his impressive showing against France.

Giovanni Van Bronckhorst is back from suspension but Artur Numan is likely to get the left back spot ahead of him because of his defensive strength.

Yugoslavia are casting themselves as rank outsiders and victims of bad refereeing.

The Balkans' lone representatives in the last eight, runners-up in Group C, have been castigated for indiscipline - they have had three red and eight yellow cards in their three games.

But they have also been applauded for playing in two of the most engaging contests in the tournament, fighting back from 3-0 down to draw with Slovenia and losing in the last seconds to Spain, 4-3.

"I just look at the facts," said Yugoslavian boss Vujdin Boskov: "I could just say we don't have players as good as Holland.

"They play in front of their home supporters and they do not have one player suspended. Also, when you look at injuries they have none. We are going to do our best, but it's going to be very difficult."

The defeat by Spain would have had been a lot more painful had Boskov's men not reached the quarter-finals, but Norway and Slovenia could only manage a 0-0 draw.

The Yugoslavs are incensed at the number of bookings they have received.

Slavisa Jokanovic, sent off against Spain by French referee Gilles Veissier, said: "It was not easy to play with 10 men against 12."

Predrag Mijatovic was also bitter about the defeat, saying: "I got the impression that the game would go on and on until they scored the winning goal."

"Up to now the ref has never been on our side," said Boskov.

"The referees are not very consistent. Other countries should have got more yellow cards. I hope that during the match against Holland we will have a good referee."

The referee will be a familiar face. Jose-Maria Garcia Aranda, the man who presided over Holland's victory over Yugoslavia at France 98, is in charge.

"In France they played better football but we would have won had we not missed a penalty," Boskov said. "Of course I hope to take revenge but I also have to be realistic."

Holland, who have won all three of their games, themselves participated in one of Euro 2000's top games when they came from behind to beat France 3-2 in midweek.

Rijkaard is wary about the unpredictable Yugoslavs, saying: "Yugoslavia are an opponent who you absolutely cannot count on.

"They have a good match mentality. They are fighters. They are also very good technical football players.

"I think they are better than two years ago, when we beat them in France at the World Cup."

There is a rift, meanwhile, between Holland's players and Johan Cruyff.

The Dutch legend has been critical of their play while commentating on Dutch television during the tournament.

When Edgar Davids was captured on television arguing in the win over France, Cruyff said: "Davids should keep his mouth shut and just play football."

Frank de Boer, whose magnificent free-kick pulled Holland level against the French, said: "He (Cruyff) had many criticisms on Davids and (Philip) Cocu while they were among the best against France.

"And what he thought about me not having too much offensive power, he forgets I'm libero and I can't just walk away from my position.

"Many people believe Cruyff because he has so much influence, and that's very annoying."

But Rijkaard said: "Johan is Johan. When he has criticism, he has to say it. There is something for us to improve. We've got to improve on losing possession."

Mateja Kezman, who completes his two-match ban, and Jokanovic are unavailable for Yugoslavia.