The 34-year-old missed Wednesday's match after sustaining an ankle injury in the quarter-final victory over Sweden, the record 112th time he represented the Netherlands with whom he was three times a losing semi-finalist in major tournaments.

Wednesday's defeat is expected to trigger a changing of the guard in the Dutch national squad with de Boer retiring and Phillip Cocu, 33, Jaap Stam, 31, and Marc Overmars, 31, among the older players who are not expected to be around by the time of the next World Cup in Germany in two years' time.

Wednesday's 2-1 loss to hosts Portugal was the fourth time he had been part of a squad that endured the agony of defeat in the last four and in a poignant moment De Boer limped across the pitch on crutches at the end of the match.

De Boer had planned to quit after Euro 2004, joining twin brother Ronald on the international sidelines after 14 years playing with some of the Dutch greats like Ruud Gullit, Marco van Basten, Dennis Bergkamp and Ruud van Nistelrooy.

De Boer was a cultured, ball-playing defender who scored 13 international goals.

He started his career at Ajax Amsterdam and made his international debut against Italy in 1990 before going to the 1992 European Championship in Sweden, where the Dutch were knocked out by eventual winners Denmark in the semi-finals.

He also went to the 1994 World Cup in the United States but was an unused substitute in the quarter-final defeat by Brazil.

The highlight of De Boer's club career was in 1995 when he helped Ajax win the Champions League, while his international peak came in 1998 as captain of the terrific side that reached the World Cup semi-finals.

The defender's raking 50-metre pass set Bergkamp up to score a dramatic extra-time winner against Argentina but once again the Dutch failed to go all the way, losing to Brazil in the semi-finals.

After moving to Barcelona along with his brother, De Boer led the Netherlands to the Euro 2000 tournament on home soil but the team again flattered to deceive.

De Boer missed a spot kick during the semi-final against Italy and then failed to convert a penalty in the shootout as the Dutch self-destructed yet again.

Frank remained at Barcelona when his twin joined Scottish club Rangers and in 2001 he was suspended for taking banned drugs.

De Boer moved to Turkish side Galatasaray last season but left after six months to be reunited with his brother at Rangers. The pair are to end their club careers together in Qatar.

Midfielder Ronald decided to turn his back on international soccer after being overlooked for the Euro 2004 warm-up friendlies but Frank soldiered on.

He had to be content with a place on the substitutes' bench until Wilfred Bouma was injured during the second match against the Czech Republic, offering De Boer a final chance on the big stage.

Immediately claiming back the captain's armband, De Boer led the Dutch to a 3-0 win over Latvia which enabled them to finish as group runners-up.

De Boer must have been relishing a last chance to win that elusive major tournament before an untypical reckless challenge on Sweden's Fredrik Ljungberg brought the curtain down on an illustrious international career.

"It was a painful way for things to end," de Boer said after hobbling out of the Dutch dressing room on crutches.

"Of course what I had in my mind was to lift the Cup. But life and football don't always go how you want them to.

"I am not an emotional guy. But I think when I sit around the table with the players for the last time and then say goodbye to everyone, then I'm going to realise that it is over."

Of the four semi-finals he was involved in, de Boer admitted it was the last one that will give him the least cause for regret.

"This one, I think we didn't deserve to be in the final," he admitted. "In 92 I think we deserved it, in the World Cup in 1998 I think we deserved it and in 2000 also.

"It is hard. We have so much quality and to stand now at the end of my career empty handed -- I would rather have finished with only 20 caps and won one trophy."

De Boer, who opted to quit Rangers after it was made clear that Ronald would not be offered another contract at Ibrox, added: "It was hard to leave Rangers.

"But I made a pact with Ronald. If Ronald was not there I would have surely stayed at Rangers because I had a fantastic time there. But I promised Ronald we would end our careers together, so why not."