The Jets continued their promising build-up to the 2019-20 A-League campaign with an emphatic 5-1 win against Edgeworth Eagles in the FFA Cup on Wednesday night, which followed a 3-2 boilover against Melbourne Victory.

They will learn after the four remaining round-of-16 fixtures next week who they will face in the quarter-finals.

After the disappointment of last season, when the Jets missed the play-offs by five points after finishing runners-up 12 months earlier, Merrick spent countless hours searching for imports he felt could reinforce his roster.

He emerged with attacking midfielder Nick Fitzgerald, a young veteran of 169 games at his previous four A-League clubs, former Central Coast defender Matt Millar, Panamanian striker Abdiel Arroyo and former Ireland international and Norwich City club legend Wes Hoolahan.

All four have wasted no time in convincing Merrick they will be valuable assets.

"We've added four really high-quality players, I think ... we've put together a very good squad at a bargain price," Merrick told the Herald.

"I think we've got probably the strongest squad since I've been at the club, for three years. Having said that, we can't get carried away.

"We've played two or three local sides, and we gave Victory a two-goal start [in the FFA Cup] before we came back, so I think there's room for improvement. But I think we've got a solid team."

Merrick added that the overall fitness levels of his players was cause for optimism.

"I think we're ahead of any other pre-season I've done at this club," he said.

Newcastle's senior players, skipper Nigel Boogaard, defender Nikolai Topor-Stanley, midfielder Ben Kantarovski and goalkeeper Glen Moss, have missed the two cup matches as Merrick gradually prepares them for the long season ahead.

Boogaard had off-season knee surgery, Topor-Stanley and Kantarovski have calf and groin complaints respectively, and Moss suffered a bruised foot at training recently, creating an opportunity for understudy Lewis Italiano.

All four are expected to be fit for Newcastle's season-opener season-opener against the Mariners in Gosford on Saturday, October 19.

"Each one has a modified program," Merrick said.

"You can't expect a 30-odd-year-old to train as hard as a 25-year-old ... I'm not worried that they're not taking part. I want them to be fully fit, and they're pretty close to it."

The Jets are now trying to lock in some trials against A-League opponents to round out their pre-season.