The much-travelled Shrewsbury Town chief's 800th game in charge as an EFL manager arrived on Wednesday night, with Duff now assigned with pitting his wits against the 58-year-old, who handed him his big playing break at Cheltenham, this weekend.

Duff said: "He sort of picked me up by my bootstraps at 17. I was at Cheltenham and luckily because of him, we got three promotions in five years which managed to get me into League One from non-league.

"He was a huge influence on that part of my career. He is the one that took me to Burnley and tried to take me to Stoke after giving me an opportunity in a Cheltenham shirt. I have a lot to thank him for."

Duff knows Cotterill well enough to know that he will not have missed a trick tactically ahead of Saturday's meeting, with his longevity in the game being testament to his knowledge and preparedness.

He continued: "He is probably one of the most experienced managers in the league and he's worked at big, big football clubs.

"To have that longevity and number of clubs means you are doing something right because quite a lot of managers come out of one club and can't get back in.

"That shows the knowledge he has got and Shrewsbury are benefitting from that knowledge.

"They will be organised and have good details on us with strengths and weaknesses and will be a tough nut to crack.

"On the managerial side, when I first got the (Cheltenham) job, he was out of work and used to come quite a lot.

"We changed to a back five or three and I used to pick his brains on that.

"I still have a lot of time (for him). We wouldn't just walk past each other in the street, we'd have a coffee and a chat. I owe him a lot.”

Duff admits he has 'food for thought' regarding his midfield make-up on Saturday - following Adam Phillips's impressive contribution in the FA Cup win at Bolton.

Phillips made a statement with his first Reds goal, an excellent 20-yard strike, having been brought into the starting line-up for Josh Benson.

Barnsley FC boss Michael Duff's debt of thanks to Shrewsbury Town chief Steve Cotterill