Notts County manager Martin Allen said injuries to both centre-backs played a part in the Johnstone's Paint Trophy exit against Chesterfield.
Mike Edwards [head] and Krystian Pearce [knee] were both taken off after 15 minutes but Notts led 1-0 against 10 men at Meadow Lane before losing 3-1.
Allen told BBC Radio Nottingham: "I'm disappointed to lose but I don't think it was through a lack of effort.
"The attitude was spot on but when you lose good players it's a big blow."
Allen added: "To lose two centre-backs in the first 15 minutes was particularly disappointing.
"Edwards has gone to hospital and Pearce's knee will be assessed. I just hope they are both OK."