Newcastle Knights coach Adam O'Brien has explained the main reason behind halfback Jackson Hastings being axed from the NRL team for this week.

After back-to-back losses, O'Brien decided to shake up his halves for this weekend, promoting Jack Cogger to the starting halves and dropping Hastings down to reserve grade in the NSW Cup - Jayden Brailey has been selected and will be named on the interchange bench.

When news initially hit on Tuesday that Hastings was set to be dropped ahead of the 'Tuesday Team List' announcement, Fox Sports reported that he decided against training with the NSW Cup side and instead went home.

However, O'Brien insisted that the halfback decided to take some time away from the team on Tuesday and was then among the first players to attend training the following day on Wednesday morning.

โ€œThis isn't the end of Jackson,โ€ O'Brien said via The Daily Telegraph.

โ€œI want to make that very clear. This isn't a decision that I've taken lightly. I'm not saying we didn't get the result because of Jackson Hastings.

โ€œWe needed a spark of energy. We are back here at home. I don't want to wait until three quarters into the year to bring some energy into the team.

โ€œIt remains to be seen if it's the right call. We've been clear on what he needs to work on and he is more than capable of doing it.

โ€œIt'll give him a chance to work on his game without the stress. But he is a big part of our squad.

โ€œHe was a big part of our success last year and he will be a big part of any future success we have.

โ€œI don't want to understate what he has done for us. He will feature in our team again.โ€

The axing of Hastings makes him the fourth halfback to be dropped in the opening three rounds of the season, alongside Sean O'Sullivan (The Dolphins), Lachlan Ilias (South Sydney Rabbitohs) and Jayden Sullivan (Wests Tigers).

O'Sullivan and Ilias will play in the QLD Cup and NSW Cup this week, while Sullivan will start from the interchange bench in favour of Aidan Sezer.