Blues have already had the pleasure of Mr Gallagher refereeing one of their games this season whilst the Oxfordshire official has also taken charge of two Man Utd fixtures this season.
Dermot Gallagher was the man in the middle for Blues' 1-0 home defeat to Crystal Palace back on 30th October. Defender Matty Upson was the only Blues player booked that day.
The last time Gallagher took charge of a United game was back on 26th December. He was the referee in charge of their 2-0 home win against Bolton. No player from either side was cautioned that day.
Prior to the Bolton game Gallagher had taken charge of United's 0-0 home draw with Everton at the end of August. No United players were booked on that occasion either.
In total then, Dermot Gallagher has refereed 13 Premier League games so far this season in which he has handed out 27 yellow cards and just the 1 red.
Mr A Butler and Mr P Canadine will be Dermot Gallaghers assistants for the game at Old Trafford on saturday.
For a detailed head-to-head between the two sides, click here