Delph replaced Aston Villa's Craig Gardner, who scored England's second goal in a 2-0 win in Sheffield over the Czech Republic .
Spurs' loan striker Fraizer Campbell opened the scoring with a chip from a tight angle after Peterborough keeper Joe Lewis' long ball forward.
Spurs' Jamie O'Hara also missed penalty.
England U21: Lewis (Fielding 31), Cranie (Naughton 60), O'Hara (Bertrand 80), Muamba (Cork 61), Stearman, Onuoha, Lennon, Gardner (Delph 86), Campbell (Ebanks-Blake 69), Vaughan (Lallana 86), Kightly.
Subs Not Used: Johnson.
Booked: Campbell.
Goals: Campbell 10, Gardner 56.
Czech Rep U21: Divis, Halama, Heidenreich, Mazuch, Svec (Lecjaks 78), Kudela (Polak 87), Horava, Dockal (Gecov 40), Micola (Zeman 65), Moravek (Blazek 65), Pekhart (Reznicek 46).
Subs Not Used: Vaclik.
Booked: Svec, Heidenreich.
Att: 18,735.
Ref: Cuneyt Cakir (Turkey).