By Will Kuhns in Washington, D.C.

Expect changes in the U.S. men's national team's lineup tonight when it hosts Panama in World Cup qualifying (live on ESPN2, 7:30 pm ET/4:30 pm PT; delay on Telemundo 11:30 ET/PT)

For its 2-0 victory in El Salvador, the U.S. team played in a 3-5-2 formation with two attacking midfielders — Landon Donovan and Clint Mathis. But Panama's offense gave the United States fits during the teams' 1-1 draw Sept. 8 in Panama City, so Coach Bruce Arena is likely to switch to a four-man defense.

And in previous ''double dates'' such as this with two games in rapid succession, Coach Bruce Arena has altered his personnel considerably between the two games. One required switch will be for defender Cory Gibbs, who is suspended for this match because on Saturday he received his second yellow card of the competition.

In the absence of midfielder Claudio Reyna, the U.S. team struggled to maintain the kind of territorial dominance it had in the first meeting against El Salvador. Mathis, in particular, had trouble connecting his passes while the three defenders seemed hesitant to play balls forward into the center of the field. DaMarcus Beasley moved inside from the flank during the second half and unsettled El Salvador's defense.

A win tonight sends the United States comfortably through to the final round of qualifying for the 2006 World Cup. But the U.S. team does not expect beating Panama to be a walk in the park.

''This is a very good team that's on a big roll,'' defender Eddie Pope said. ''They've got two big guys up top, most of their goals have come off crosses. They like to get the ball wide and whip it into the box, jump on the balls that we clear out and then try to come at us again. For us, we have to play well defensively and take advantage of our opportunities going forward.''

Arena wants his team to possess the ball better than it did against El Salvador, when it often lost possession in the middle third of the field. Panama is more dangerous on counterattacks.

''So far in the competition, they've been as impressive as anyone in the group,'' Arena told The Washington Post.