The Phoenix suffered back-to-back 2-1 losses to Adelaide and then Perth during their venture to Australia, which has left them in fifth place on the table.
"What we know now is we are not good enough yet to take points off the teams that are at the top of the ladder when we are away from home and we've got to change that," Merrick said.
The veteran coach knows what his men need to do to produce the right results and it starts at practice.
"It's about getting things right on the training field and it's about solid defence that doesn't concede a goal after two minutes and then play catch-up football," Merrick said.
"It's the work in the front third that we've been spending time on in training."
Wellington have only kept one clean sheet in seven games this season and they need to find a way to tighten up at the back if they want to be a playoff contender.
The Phoenix will have the opportunity to get back to the winner's circle on Sunday when they host Melbourne City at Westpac Stadium.
Wellington will be able to call upon attacking midfielder Michael McGlinchey who missed the loss to Perth last weekend due to the birth of his second child.
"It's great to have a player like him coming back," Merrick said as he noted that despite City's indifferent start they were still a tough prospect.
"There's no easy games, home or away, every team can take points off every other team and I think they're a good squad that we must make sure we respect."
City, who were the A-League's big spenders in the off-season, have conceded 14 goals in seven games this year on their way to one win, three draws and three losses.
Because of the woeful beginnings for Western Sydney, Central Coast, Newcastle and Brisbane, City's mixed record has them in sixth place.
The Phoenix have had issues with converting their penalty kicks this season but they may have found a solid option in striker Roy Krishna who nailed his chance against Perth.
The Fijian international hasn't always been a regular starter during his time with Wellington but Merrick confirmed that Krishna would be the first-choice option on penalties when he was on the field.
"He's been playing really well," Merrick said of Krishna.
- Daniel Richardson of NZME. News Service
