MLS' newest expansion team Philadelphia Union will make their debut top flight appearance in March according to a source.

March 25 has been set for the Union's opening MLS clash and they will meet this season's new addition, Seattle Sounders, at Qwest Field which will kick-off the 2010 MLS season.

The Union will play their first home game against DC United on April 10 at Lincoln Financial Field whilst Union Field in Chester is being completed.