Millar's squad currently lead their qualifying table but their hopes suffered a huge setback when they suffered a 2-1 defeat at the hands of Israel in February.
Northern Ireland's hopes of qualification now rest on the results of other games and that must-win encounter with the Germans.
N Ireland U21 squad:
Tuffey (Partick Thistle), Carson (Sunderland), Kane (Blackburn Rovers), Casement (Ipswich Town), McArdle (Rochdale), Cathcart (Manchester Utd), Callaghan (Derry City), Howland (Port Vale), McVey (Coleraine), Turner (Bohemians), Garrett (Wrexham), Buchanan (Bury), Mulgrew (Linfield), Carvill (Wrexham), McCaffrey (Livingston), Stewart (Linfield), Fordyce (Glentoran), Ward (Chesterfield), Waterworth (Hamilton Academicals), Meenan (Monaghan Utd), Keenan (Larne), Taylor (Hearts).