Sheffield United: Should Norwich City's midfield maestro receive greater protection?

Farke issued the plea after watching the former Getafe player limp-out of last week's victory over Birmingham with a suspected dead leg following a series of first-half challenges.

Although he expects him to recover in time to face Chris Wilder's side, Farke expressed concerns that Buendía is becoming a marked man among opponents after helping City climb to second in the table.

"This is the second time in a pretty short period he has had this injury," Farke complained. "I think there were many, many fouls on him, some really nasty fouls and sometimes as a head coach you wish a player like that can be more protected from the officials."

"No complaints from us," Farke added. "It is a little bit his style of play as well why he has fouled so much because he is always searching for these one versus one situations.

"He is a key player for us and we want him back in his rhythm. I hope he can come back for Sheffield United."

Although his comments could annoy United as they prepare for a potentially pivotal fixture at Carrow Road, Farke's words do not appear to contravene Football Association regulations because he does not reference James Linington, who will oversee this weekend's match, or any other official by name. 

Wilder was also critical of referee John Brooks' performance during United's defeat by Swansea City four days ago but did not question his integrity.

Speaking before the visit to South Wales, where he was also frustrated by match-winner Oliver McBurnie's decision to confront the fourth official following a challenge on one of his team mates, Wilder admitted players "diving, rolling about and crowding around referees" was a more important issue than 'Spygate'; the controversy engulfing Championship leaders Leeds after Marcelo Bielsa revealed he has been secretly observing opposition training sessions.

Farke's employers have taken a different approach to the matter, adding their name to a communiqué also signed by 10 other clubs demanding 'full disclosure' once the English Football League and FA conclude their investigations.

Like Wilder, whose fourth place side will climb above City if they win in Norfolk, Farke has confirmed he would not be adopting Bielsa's controversial tactics. "With this situation I will speak about quality, style and class," the German said. "We are a club full of quality and full of class.

"Everyone is responsible how he prepares his team for the challenge. We all have different ways and different styles.

"In general, I just can say we as a club don’t send any spies out and if there is a session behind closed doors we respect that."

"I am full of respect for the career of Marcelo Bielsa," Farke added. "The way they are playing is a big credit to him.

"Maybe 10 years ago it was the case that one day before a game there was a tactical session when you play your starting line-up. Nowadays I don’t think there are any secret set-pieces or whatever.

"Maybe you can see if the players are in a good mood or the coach stays indoors at the training ground but there is only so much you can find out."