The mentality of Barnsley’s players was not in question on Tuesday night as they let two points slip at home to Port Vale, and it will have to be sharp again on Saturday when the Reds visit Cambridge United.

Duff had raised the need for his players to be mentally tough this week in games against two unfashionable League One teams , having risen commen dably to the task of taking on, and beating, Sheffield Wednesday 10 days earlier.

And while his players may have lacked physical strength in not being able to close out victory against Vale, Duff feels their attitude was not in question.

"I think the mentality of the team was excellent, other than the first 10 minutes,” he said. “If you compare it to the Wycombe game (lost 3-0) it was nowhere near that, but I talked about the 36 games either side of the five brilliant ones and the five awful ones, they’re the games you need to eke out that win.

Michael Duff, manager of Barnsley. (Picture: George Wood/Getty Images)

"We were good enough to win (against Vale), when we watch the video back we’ll see there’s lots of positives, the chances created, they’re not just in my head, they’re facts, so there’s things to work on,

"We’re disappointed, it’s two points dropped, but it wasn’t through a lack of attitude, it was just through maybe a lack of a physical edge and a lack of know-how.”

Cambridge have won four out of four at home this season ahead of the visit of Duff’s Reds on Saturday.

"I just warned the players after the game – Cambridge have been on the up for two years, they've got the same team, they’re street smart, they’ve got good quality and they’re a tough nut to crack,” said Duff.

"It’s not Sheffield Wednesday, it’s not Ipswich, but you’ve got to have the same mentality and attitude otherwise it will be a difficult day.”

Barnsley FC showed mental strength despite Port Vale setback