With Mike Ashley effectively funding both clubs it was no surprise to see an Ashley appointee, Rangers chief executive Derek Llambias come out and say McDowall is wrong to say he has been told he must select five loan signings from Newcastle.
McDowall claimed Llambias and chairman Sandy Easdale told him the quintet - whose parent club are owned by Ibrox shareholder Mike Ashley - must play.
But Llambias said: "There's no way the board is picking the team.
"In any loan the players bolster the side and give the squad more depth. That's exactly what is happening here."
Midfielders Gael Bigirimana and Haris Vuckic and defenders Kevin Mbabu, Remie Streete and Shane Ferguson joined from the English Premier League side on Monday.
Interim manager McDowall, who took over from Ally McCoist when he was placed on gardening leave on 19 January, recently handed in his notice to resign.
He is now working a 12-month notice period.
"I have told the guys I am happy to take the team. So I am not going to complain," McDowall said at a media conference earlier on Thursday.
"I will carry out the instructions that they give me and do my best. I have a job to do and I am happy to do it.
"The boys have come up to play and they will play. That's just how it is."
The spat is hardly likely to enhance McDowall's chances of surviving the next 12 months as boss.