Millwall's Under 23s suffered a 2-0 loss to Cardiff City in the Professional Development League on Monday afternoon.
Chanka Zimba and Isaak Davies his the target in either half to condemn Kevin Nugent's side to defeat.
Sean O'Brien was at the heart of The Lions' limited attacks, but found George Ratcliffe in inspired form, most notably tipping a long-range effort over the crossbar in the first-half.
Abdul Abdulmalik made a return to action from the bench just after the hour-mark.
Next up for Millwall's Under 23s is the visit of Queens Park Rangers - at The Den - on Friday afternoon. Tickets will be on sale in due course.
Millwall: Gillmore, Walker, Adom-Malaki (Boateng 46'), Penney, Okoli, Topalloj, Davis, Allen, Briscoe (Cotton 77'), O'Brien, Drozd (Abdulmalik 62'). Subs not used: Evans, Smith.