Aside from notable absences, including Freddy Adu, the players summoned to Home Depot Center this week by U.S. U-23/Olympic coach Peter Nowak are expected to fill a few vital slots in the squad he'll take to Beijing in August, assuming the U.S. qualifies.

Eighteen MLS employees have been summoned yet several others could be in the mix as Nowak decides on which positions to use overage players, of which three are permitted.

One could envision, for example, Nowak calling upon Landon Donovan to supplement the forward line, or a Chris Albright at right back, or any one of several central defenders.

Considering past Olympic overage choices have included Brad Friedel, Kasey Keller, Alexi Lalas, Jeff Agoos, Frankie Hejduk, and Chris Armas (who missed the 2000 Olympics because of an injury), the choices can be critical in a tournament that is officially designated as an under-23 competition but often features teams of widely different compositions.

Most European countries send their U-21 teams to the Olympics, using the competition as an addendum to the U-21 schedule that includes a European Championship for that age group.

African and Asian countries usually try to field their strongest squads, contingent upon player availability due to club commitments, which for the most promising players in their late teens and early 20s can be considerable.

The prospect of Adu and Jozy Altidore starting up front is an exciting one, but throwing a pair of teenagers (Adu will be 19, Altidore just turned 18) into the pressure-cooker of an Olympic tournament is daunting.

If Altidore moves to Europe either during the January transfer window or next summer, his Olympic participation might be jeopardized.

If DaMarcus Beasley recovers from his knee injury in time, he'd be another possibility as an overage player, but on the other hand, would Glasgow Rangers welcome the idea of him rehabbing just in time to miss preseason training and league matches?

Adu, likewise, could be constrained by Benfica if he continues to score goals and contribute to the attack.

While clubs are obligated to release players for the Olympic tournament because it is an official FIFA competition, past history suggests many clubs will block efforts to ship players off to Asia. And since Nowak can't count on any of his European players being released for the qualifying tournament in March, the MLS contingent is likely to comprise most of the players he'll use to qualify for Beijing.

(Overage players can only be used in the Olympic tournament itself.)

Two European-based players are at HDC this week: forwards Sal Zizzo (Hannover) and Charlie Davies (Hammarby IF).

The only MLS teams not represented on Nowak's roster are Chicago and D.C. United. RSL leads the list with three (goalkeeper Chris Seitz, defender/midfielder Nathan Sturgis, and forward Robbie Findley). Findley is one of six rookies selected, including MLS Rookie of the Year Maurice Edu of Toronto.

The Americans will train at HDC daily until Saturday and then head off to China for a pair of games against the Chinese U-23 team.

Camps are scheduled for January and February in California and Florida. The CONCACAF qualifiers are scheduled for March 11-23 in Los Angeles, Tampa and Nashville. The eight-team tournament will send the two finalists to the 2008 Olympic Games in Beijing.

U.S. UNDER 23 MEN'S NATIONAL TEAM ROSTER

GOALKEEPERS: Zac MacMath (St. Petersburg, Fla.), Chris Seitz (Real Salt Lake)

DEFENDERS: Hunter Freeman (New York Red Bulls), Patrick Ianni (Houston Dynamo), Jon Leathers (Furman University), Mike Randolph (Los Angeles Galaxy), Nathan Sturgis (Real Salt Lake), Tim Ward (Columbus Crew), Marvell Wynne (Toronto FC)

MIDFIELDERS: Arturo Alvarez (FC Dallas), Maurice Edu (Toronto FC), Michael Harrington (Kansas City Wizards), Aaron Holbein (Kansas City Wizards), Stuart Holden (Houston Dynamo), Sacha Kljestan (CD Chivas USA), Dax McCarty (FC Dallas)

FORWARDS: Josmer Altidore (New York Red Bulls), Adam Cristman (New England Revolution), Charlie Davies (Hammarby IF), Robbie Findley (Real Salt Lake), Robbie Rogers (Columbus Crew), Sal Zizzo (Hannover 96)