Carlos Carvalhal has warned his Owls players against complacency as they prepare to face rock-bottom Rotherham United.
Wednesday welcome their South Yorkshire neighbours to Hillsborough knowing three points could catapult them back into the Championship top-six.
But Carvalhal is refusing to underestimate the threat the Millers, who triumphed 1-0 on their last visit to S6, will pose.
“The score last season has put our senses on alert,” said the Portuguese head coach, who will check on midfielder Barry Bannan (foot) today. “We are more alert now.
“All the teams are dangerous in the competition. There are no easy games. We respect Rotherham. I don’t think the Rotherham game will be more easy than Barnsley.
“It will be the same difficulties but they will create different problems to Barnsley.”
Interim Rotherham manager Paul Warne has won one of his three matches in charge but they remain 12 points adrift of safety.
“Rotherham beat QPR and were winning 1-0 at Fulham,” said Carvalhal. “They are more compact and solid than in the past. That is the reality.
“They are better now in previous weeks.
“It is a game we must play with patience but, at the same time, we must understand how they can do damage to us. We will try block these kind of situations to stop them being a threat.”