Arena - has a goalkeeping decision to make. (Allsport)

Click here for more USA news
Click here for more World Cup news

American World Cup coach Bruce Arena is unsure who will be his goalkeeper against Portugal.

Arena is considering rotating Tottenham Hotspur goalkeeper Kasey Keller and Blackburn's Brad Friedel in the group stage because he cannot divide the two on form, or experience.

Arena is now considering three possible options for who stands between the sticks.

"One, is we go with the same goalkeeper in all three games. Two, is we split them in games one and two. And three, is we take it one game at a time," he said.

"The decision is going to be based on who gives us the best chance to win.

"It's not sentimental... if it was sentimental, I would give myself a chance to play. That would not give us the best chance to win."

In the 1998 World Cup Friedel was given the squad's number one jersey, but had to sit by and watch as Keller started in both of the America's first two group match defeats against Germany and Iran.

Those losses eliminated the United States team and Friedel was picked for the third game against Yugoslavia, which ended in a 1-0 loss.

Friedel, 31, has 76 caps while Keller, 32, has 60.

Both had successful seasons in the Premiership.

Friedel was Blackburn's first-choice starter all season, while Keller took the chance provided by Neil Sullivan's injury to become Tottenham's starting goalkeeper in the final seven games of the season.

Friedel and Keller have split most of the time in goal for the American team this year.

Because he was free of first-team commitments for much of the season, Keller was able to play for the United States in 11 games while Friedel played in only four.

Tony Meola, 33, was the starter at both the 1990 and 1994 tournaments but is the number three goalkeeper this time and would play only if both Friedel and Keller were unavailable.

After the Portugal match, the United States also meet Poland and hosts South Korea in Group D.