All four were part of Monk's coaching staff at Middlesbrough and were placed on gardening leave after he was sacked. They are also being sued by Middlesbrough, who fear the coaches may be followed by an exodus of players they had helped sign.
The barrister acting for Middlesbrough told London's High Court that all four members of Monk's team had clauses in their contracts prohibiting them from working together or working with Monk for a rival Championship club before Dec. 28, 2018.
"There is a real risk that Middlesbrough will lose players to BCFC if it continues to employ each member of the backroom team at the same time as each other and/or Mr Monk," Ian Mill added.
"A number of Middlesbrough's current players... were recruited or favoured by different members of the backroom team and remain loyal to them.
"BCFC's employment of the backroom team is therefore likely to give it ongoing competitive advantage over Middlesbrough."
Middlesbrough are seeking damages as well as an injunction to prevent the coaches from working for Birmingham until Dec. 28.
Judge Mark Warby said he wanted to resolve the matter as quickly as possible.
"This is a case in which the answer should be arrived at swiftly following a trial in the next eight weeks," he said.
Middlesbrough are currently fifth in the 24-team Championship, while Birmingham are 20th.
(Reporting by Hardik Vyas in Bengaluru; Editing by Keith Weir)
