Merrick told The World Game that before he was appointed the Jets had made a great start with the signings of striker Roy O'Donovan and fullback Daniel Georgievski.
The former Melbourne Victory and Wellington Phoenix coach insisted Newcastle now has to finish the job.
"As a priority I would like to sign some experienced, battle-hardened, attacking-type players in particular," Merrick said.
"Roy and Daniel have a proven track record which speaks for itself and are very good signings and hopefully four or five more players can be recruited prior to the season.
"Three of these players must have experience, good technical skills and demonstrate a real commitment to winning matches and providing on-field leadership."
Merrick will be looking for one or two promising young players among those new signings as well.
Since Merrick's appointment on Tuesday, the Jets have moved quickly to make room on their roster and Labinot Haliti, Andrew Hoole, Daniel Mullen, Mateo Poljak, Morten Nordstrand, Tomislav Arcaba, Ma Leilei, Harry Sawyer and Joel Allwright won't be offered new contracts.
Kosta Petratos and Mario Shabow were also signed from other clubs ahead of Merrick's appointment and Ben Kantarovski has been offered a new deal.
Asked if he was looking for players both from within Australia - the A-League and the various National Premier League competitions - and overseas, Merrick replied: "Mostly current A-League players and perhaps two more visa players."
Numerous A-League players remain unsigned for next season and some of those, including midfielders Mitch Nichols and Marcelo Carrusca, have already been speculated upon as potential Jets targets.
Adelaide United have made no attempt to re-sign Carrusca, whilst Nichols was on Thursday included in a list of player departures from Western Sydney Wanderers.
Nichols is seeking to play in Europe, but it remains to be seen whether he can find a suitable club there.
Socceroo forward Nathan Burns, who had a loan stint at the Jets in season 2013-14 and played under Merrick at Wellington Phoenix the following season, has recently been struggling to get J-League game-time at FC Tokyo.
But Merrick said any move to try to get Burns would face hurdles.
"Nathan is an excellent player who I have coached previously, but he is on an outstanding salary at Tokyo FC," Merrick said.
"It is difficult to compete with those finances. Perhaps another similar player who is affordable will appear."
Merrick, who won two championships with Melbourne Victory, said he was convinced the days of regional clubs like Newcastle winning titles were not over. He said that as long as they recruited well and were able to keep their team on the field they could be very competitive.
"Sydney rarely used more than the same 15 players in winning the competition and all teams can budget to sign a squad with that number of quality players," he said.
"I had a similar situation at Victory in season 2006-07 with a smaller budget, as did Adelaide in the 2016 grand final.
"I'm confident we can make the finals next season and I believe the players will learn to cope with the pressure associated with higher levels of expectation.
"I can’t guarantee wins every week, but I can guarantee the starting XI will comprise of players who selflessly commit to playing an attacking brand of football for this club with the intent of winning."
Merrick, 64, said he would never stop learning as a coach.
"I have never considered the number of revolutions around the sun to be a measure of someone’s ability, motivation or suitability for a coaching role," he said.
"I personally would prefer to be judged on my physical fitness for the role, football knowledge, match experience under stress and ability to teach and communicate with athletes.
"In my opinion, as a high-performance coach I haven’t peaked yet."
