He over-stretched for a ball and pulled a groin muscle and had to be replaced by Bobby Hassell after 16 minutes. Reds physio Matt Konopinski told www.barnsleyfc.co.uk:
"Darren picked up a groin injury in the first half against Watford last week. He went for a scan on Monday morning and this showed he had suffered a Grade Two tear of his abductor longus muscle.
"He will be out for around four weeks".
Moore joins Iain Hume (skull), Simon Whaley (foot), Martin Devaney (thigh) and Anderson de Silva (suspended) on the sidelines.