Speaking after his team slumped to their fourth straight loss in dismal fashion against the Knights, McGregor spoke of the true toll the de Belin saga had taken on the club.

"I hope that didn't have an effect on the performance today ... some say it may have because Jack is a very well liked person and an important part of our football team," McGregor said.

"There's feeling there, there's definitely emotion there for sure. Whether that played a role in today's performance or even in my build-up I'm not sure, subconsciously.

"Certainly he is a big part of our lives. But he wasn't there today and there 17 players and coaching staff who didn't do what they needed to do."

McGregor revealed the club expected de Belin to be available for the match in Mudgee on Sunday, such was the Dragons' confidence in the Federal Court challenge of the NRL's new no-fault stand-down policy. De Belin's court bid failed last Friday.

"To be totally honest we all expected him to be available today, but he wasn't so we had to move on pretty quickly from that," McGregor said.

"I spoke to Jack and his next move I'm not sure on. I can't comment on that much further until we get home and sit down and chat."

The de Belin drama has clearly hampered the Dragons both on and off the field.

Off field, de Belin continues to train with the club's top squad despite almost certainly being unavailable for the remainder of the year. The forward has pleaded not guilty to a charge of aggravated sexual assault in Wollongong court.

That won't change, according to McGregor, who was steaming after his side's 45-12 loss.

"I haven't really even thought of that but he's a part of our club," he said.

"He's got the assumption of innocence until he gets his opportunity in court, which he's not getting at the moment anywhere else."

On field, the absence of the NSW Origin representative, along with Korbin Sims and Jeremy Latimore through injury, has left the Dragons coach with little choice but to play Paul Vaughan, James Graham, Tyson Frizell and Tariq Sims for additional minutes on a weekly basis.

Tired bodies have seen the middle third of the field leak metres and points as a result and now McGregor has forecast swinging the selection axe after a dreadful performance against Newcastle.

"We can use the experience we've got on the sidelines, we can use the learning that we're getting," he said.

"But the same people are making the same errors and poor reads on a weekly basis."

Four straight losses will trigger change, as McGregor fears some players may have become too comfortable after a hot start to the season.

"When there is a lot of people missing with experience you can get comfortable," he said.

"I'm not saying that's the case at the moment ... and it would be disappointing if it is.

"But we've got a lot of guys still learning their craft. And learning at tough times.

"Right now, we're halfway through the year so if we're still making the same errors, and giving away the same sort of penalties, the same people are doing it that means they're not listening."

Trent Merrin's name has once again been raised as a potential replacement for de Belin, with the Dragons expected to be given about $270,000 in salary cap exemption with their star lock unavailable for selection.

"I have got Ian Millward, who looks after our retention and recruitment and managing the cap," McGregor said.

"And he's been working hard at it for quite some time and different alternatives.

"I didn't want to talk about anything until next week. I just wanted to focus on today and get over the Jack de Belin decision."