After Newcastle lost their first two games of the year, Knights coach Adam O'Brien brought in recruit Jack Cogger to replace last season's first-choice halfback Hastings.

The new halves combination had its moments as the Knights ground out a 14-12 win over Melbourne on Sunday, but five-eighth Gamble said he and Cogger would need time to click.

"We were a bit rocks and diamonds there at times," Gamble said. "We had some pretty good stuff but there were a couple of times we were on different pages. That's just through lack of (familiarity)."

Gamble said he had barely crossed paths with Hastings since the 28-year-old was axed from the NRL side.

"It's been a bit of a whirlwind for him. I don't think he expected it," Gamble said. "It's a tough position to be in for a bloke who's played a lot of NRL."

O'Brien has stuck with Cogger at halfback and Gamble at five-eighth for Sunday's clash with the Warriors despite a promising showing from Hastings in NSW Cup.

Hastings's relegation so early in the season has given Gamble cause to reflect on his own place in the side.

"After two games, we hadn't been playing our best footy and the coach made a decision early," Gamble said. "It sent a message to myself without really saying anything - I've got to be on my game. I can't put in too many bad performances in a row. I had a hard look at myself this week. It could've been me that went down (to reserve grade)."

Aware of online commentary saying he had been fortunate to avoid the axe, Gamble has pulled the plug on his social media - at least for the time being.

"It's very hard to not read things about yourself. It's very hard to not buy in to those things," he said.

"Quitting social media won't be something I'll do forever, but until I find some form again and I'm really comfortable with the way I'm playing, I'll probably stay off it."

Hastings, who joined Newcastle from Wests Tigers last year, on Sunday steered the Knights to a 50-24 defeat of North Sydney in the NSW Cup.

Gamble said he expected the Great Britain international to press his case for a swift return to the top level.

"My hat goes off to him because he went out there and played Cup and played really well," Gamble said. "I'm sure he'll be back in the team soon enough.

"The club's in a good position. If there's an injury, or myself or 'Cogs' aren't playing, Jacko's right there.

"It's a good headache for the coach and the club to have, and on the flip-side of that, it's good for myself and Cogs to know that we have to be on our game."