Barnsley are awaiting the results of a scan on leading scorer Craig Davies.
The Wales international, who has eight goals this season including four in one game against Birmingham, went off with a hamstring injury in the final minute of
Saturday's 1-0 win at Charlton.
Boss Keith Hill has confirmed the 26-year-old will definitely miss Tuesday's home game against Crystal Palace.
And asked how long Davies might be out, he told
BBC Radio Sheffield:
"It could be anything between two and six weeks."
Davies has been a big success at Oakwell,
since joining the Tykes from Chesterfield before the start of last season,
and won his first Wales cap for almost five years when he came on as a substitute
in the World Cup qualifying win over Scotland earlier this month.
His injury means Marlon Harewood looks certain to step up from the bench to lead Barnsley's attack.
However, Hill admitted that if Davies is likely to be absent for more than a fortnight, he would look to bring in a player on loan.
"We'll wait until the results of the scan," he added. "We'll assess the options we have going into the weekend's game."
Meanwhile, Barnsley are hoping Egyptian striker Mido will be available in the not too distant future after he played 70 minutes for the club's development side on Monday and scored from the spot in a 2-1 defeat by Huddersfield.
The former Tottenham and Middlesbrough player joined Barnsley in June but has yet to make his first-team debut
after rupturing a hamstring while warming up for a pre-season friendly against Doncaster.