The United States beat Norway Japan and Guatemala recently with a team mainly comprising players from Major League Soccer. The game against Poland represents Arena's last chance to see most of his Europe-based players before he has to name his World Cup squad.
"I don't think the result of the game is that important as much as is the performance of the players Arena said Tuesday ahead of a training session. "Some of the players are on the fence so to speak and have their last opportunity."
Arena has at his disposal 11 players from Europe and eight from MLS. Since the fixture date is the only one recognized by FIFA before the end of the European season it's the only time European clubs are required to release players for duty.
Arena also said it was a "big plus" to play at Kaiserslautern's Fritz-Walter-Stadion where his team will face Italy on June 17 in its second World Cup match. The United States will be in a tough first-round group also featuring the Czech Republic and Ghana.
"For our players it's also very good for them to be in a venue where they also get to play Italy and feel somewhat comfortable in this venue before we actually come back Arena said.
This region in southeastern Germany is home to the Ramstein air base and 50000 US military personnel and their families. Arena said he hoped for a strong following at the June 9-July 9 tournament.
For Poland's foreign-based players it's a first chance to impress coach Pawel Janas.
Midfielders Miroslaw Szymkowiak and Jacek Krzynowek are both healthy after leg injuries early this year and Celtic striker Maciej Zurawski has found form after also missing time because of a leg injury.
Much like Arena who said it was impossible to find teams matching those his team will face at the World Cup Zurawski said the friendly was more about getting his players reacquainted.
"I treat this as a friendly during which you have to check your condition and work on some new technical aspects of the game he said. "It's not about whether they have a similar style of play to Germany or Costa Rica."
Poland will face those two countries and Ecuador at the World Cup although the team is at an earlier stage in its preparations because its league is on its winter break.
"Only in a month or so will we be in better game shape Zurawski said. "The United States has already played a couple of warm up matches so they are at a different point in their preparation."
This is the first time the two teams have met since they drew 1-1 in July 2004. However Arena's only win in 10 games in Europe was 1-0 over Poland in March 2004.
Poland beat the United States 3-1 at the 2002 World Cup but failed to get past the first stage.