Apparently it is possible to have too much success.

At least that's the opinion of Vicente del Bosque, who has seen Spanish soccer achieve unprecedented levels of success in recent years.

The national team has won the last two European Championships as well as the 2010 World Cup. On the club level, three Spanish teams — Barcelona, Real Madrid and Atletico Madrid — went down to the final weekend before deciding this season's La Liga winner. And all three teams reached the quarterfinals of the Champions League, with Real Madrid and Atletico meeting in last month's final.

That means half the 30 players del Bosque named to Spain's provisional roster were playing important club games less than a month before the World Cup opener.

The physical toll of that worries Spain's coach.

"There is a bit of concern about the condition of the players, to see what shape they are in," del Bosque said in an interview posted on the national team website.

"You can never expect all the players to turn up in perfect shape, and it's the same for all the national teams. All the players who are taking part in the World Cup have had seasons with a lot of tough games."

For Exhibit A, the 63-year-old coach need look no further than his own front line, which could be missing Brazilian-born striker Diego Costa when Spain opens World Cup play against the Netherlands on June 13 in a rematch of the 2010 final. The teams are in Group B, which also includes Australia and Chile.

Costa, who was expected to play a key role for Spain, limped off the field with a hamstring injury during Atletico's final regular-season game in mid-May, then played just nine minutes in the Champions League final. Without him in the World Cup, Spain is far less threatening.

For the Dutch and coach Louis Van Gaal, success has brought different challenges. After the Netherlands lost all three group-play games in the 2012 Euros, Van Gaal was named to replace Bert van Marwijk for World Cup qualifying, and he led the Dutch to an undefeated campaign in which they outscored their opponents by 29 goals in 10 games.

That, ironically, helped Van Gaal win a three-year contract to take over at England's Manchester United — a job the coach always wanted but one it proved inconvenient to take less than three weeks before the World Cup.

"After two years, I'm totally sick of being national coach," said Van Gaal, who was planning a retirement in Portugal filled with family and golf unless the right Premier League offer came along. Now that it has, he's having to keep his eye on developments with two teams — which could prove a distraction given the stakes.

Van Gaal, quick-tempered and a stern disciplinarian, says he can handle it.

"It was always a wish for me to work in the Premier League. To work as a manager for Manchester United, the biggest club in the world, makes me very proud," said Van Gaal, who likely will make his debut in front of the Manchester United bench in July when the team meets the Galaxy in a friendly at the Rose Bowl in Pasadena, Calif. "This club has big ambitions; I too have big ambitions. Together I'm sure we will make history."

But first, the World Cup.

Brazil will mark the 62-year-old Van Gaal's first appearance on soccer's biggest stage, filling in the one glaring hole on a resume that includes titles in the Netherlands, Spain and Germany as well as a Champions League crown with Ajax in 1995 — and one major setback, which was failing to qualify the Dutch for the World Cup in 2002, the only time they've missed the tournament since 1986.

Van Gaal is already beginning to build synergy between his responsibilities with the national team and his new club team by saying Manchester United striker Robin van Persie would remain the team's captain.

"Always, you make a player captain when you have ... more or less the same philosophy, not only about football tactics but also about life," Van Gaal told the Associated Press. "So I think that's very important. I believe that Van Persie and Van Gaal [have] the same philosophy."