Bogdanovic is the Reds top scorer this season with three goals (albeit all in the Carling Cup) but turned his ankle in training on Monday and will definitely miss new manager Mark Robins' first two matches in charge against Watford and Derby.
Reds Physio Chris Burton told www.barnsleyfc.co.uk:
"Daniel went over on his ankle on Wednesday. We sent him for an x-ray which, thankfully, showed there was no fracture but there is a lot of swelling.
"He has strained the ligament on the outside of his left ankle but we will have to wait until the swelling goes down to make a complete assessment.
"Hopefully we will know more on Monday but we are looking at weeks rather than days".
Meanwhile new Icelandic signing Emill Hallfredsson played nearly all of
Iceland