Kayden Jackson netted his first goal of pre-season as Town’s U23s - also featuring Flynn Downes, Myles Kenlock and Brett McGavin - fell to a 3-1 friendly defeat at Chelmsford City.
The Clarets went ahead in the sixth minute via former Norwich frontman and one-time Blues trialist Simeon Jackson.
Town’s Jackson levelled in the 12th minute, beating former Blues academy keeper Jacob Marsden.
But ex-Town U18s striker and 2005 FA Youth Cup winner Charlie Sheringham put the Essex side in front for a second time just before the break and Adebola Oluwo increased the home team’s lead in the 64th minute.
U23s: Bort (Ridd), Alexander, Kenlock, McGavin, Smith, Baggott, Curtis, Downes, Jackson (Manly), Page (Agbaje), Crane (Valentine).