The Dragons mentor says now is not the time to make knee-jerk reactions despite their win-less NRL season start and is convinced his under fire changes will work.

McGregor has copped heat for switching Gareth Widdop from five-eighth to fullback to allow new recruit Corey Norman to combine with Ben Hunt in the halves, relegating No.1 Matt Dufty to a bench utility role.

The Dragons mentor said he was getting used to flak and claimed he had no immediate plans to slot Widdop back into the halves ahead of Thursday night's NRL clash with Brisbane.

"There's a lot of talk about making change. At the moment it is more about being calm," McGregor said.

"I am not surprised (by criticism) because it happens at our club.

"We didn't win two games in a row until round 18 last year and we have lost our first two so there is always going to be discussion about different things.

"The main talking point at the moment is the spine. But I value the quality of our players and I know they will make it work."

But McGregor did call on his pack to provide his spine more support.

"Talk to anyone who knows rugby league and the forward pack has to be dominant for the spine to be successful," he said.

"And when our forward pack has held possession for long periods of time in the first two weeks we have looked good.

"When we have turned over possession cheaply and not sustained pressure we look clunky."

McGregor also dismissed criticism of his mid-game spine changes that experts believe have also contributed to their losses.

In both defeats to date McGregor has opted to move Widdop back to pivot, Dufty to No.1, Hunt to hooker and slotted No.9 Cameron McInnes in at lock to fill in defensive gaps created by missing NSW forwards Jack de Belin (suspension) and Tyson Frizell (injury).

"The situation will determine interchange at different parts of the game - that is how we have played the first two weeks," McGregor said.

McGregor said their cause had not been helped by limited training opportunities due to their hectic schedule or the loss of Frizell, de Belin and new recruit Korbin Sims, who returns from suspension to make his Dragons debut against his former teammates.

"Since round one we have only had three training sessions including today because of the calendar, the travel that we have had to do and the turnarounds," McGregor said.

Australian Associated Press