Carlisle have reported referee Darren Deadman to the Football League over concerns about his conduct.
United player-coach Graham Kavanagh has claimed that the official shouted 'Get in, Harris', as Millwall striker Neil Harris closed in on goal during last weekend's clash between the two.
"I regarded that as being out of order and I confronted the ref. At first he ignored me, then he said he hadn't said anything," Kavanagh told the Times and Star.
"Then, 10 minutes later, he changed his story and said the reason he had said it was because he had played an advantage and it had led to a scoring opportunity, which reflected well on him as a referee.
"I told him he is supposed to be a referee, not a fan or a player, and the outcome of a chance shouldn't affect his emotions. I have been involved in the game for 20 years and never experienced anything like it. I was disgusted."
The Football League have confirmed that they are investigating Carlisle's complaint.
Copyright (c) PA Sport 2009, All Rights Reserved.