Widespread reports have claimed that Pulis, who missed out on signing targets Gylfi Sigurdsson and Steven Caulker, had numerous disagreements with Parish regarding transfer strategy.
Millen said in this afternoon's press conference: "I got a phone call from the chairman at 9pm on Thursday and I was asked to take training today and take the team tomorrow.
"Tony is single minded and he knows what he wants on the football field. The transfer dealings have frustrated us as a club. We had a brief meeting this morning and I told them Tony loved working with them. Confidence-wise, it shouldn't effect us at all."
Former Cardiff City manager Malky Mackay is currently the bookies' favourite to take the vacancy.