"For the key positions, an attacking midfielder or a striker, I'm looking for a good quality player who I feel that I can start if I need to,'' Merrick said.
Ifill's injury put a black mark on Sunday's win and Merrick said it was a huge blow for the club to lose the 106-game veteran.
"It's a major loss. He's one of the best strikers there's been at this club. He's not only a very good footballer but he's a very good person and leader. He'll certainly be missed.''
The Phoenix may also be on the look out for some defensive cover during the next month as left back Reece Caira will be away with the Australian under-22 side at the AFC U-22 Championship in Oman.
Caira has made seven starts at left back for the Phoenix this season - although Manny Muscat has been preferred there in recent weeks - and Merrick said they may take a developmental look in regards to filling Caira's absence.
"We'll have a look around because we are allowed to bring in a player over that month-long period,'' Merrick said. "So we'll have a look around and that's quite exciting, we might discover some talent somewhere and bring him in and it's almost like a trial period to decide then if we want to sign him for the long term.''
The Phoenix are in the middle of a busy stretch where they will play four games inside 14 days but Merrick said, after they picked up their first win of the season against Sydney on Sunday, fatigue won't be a factor.
"I think at the moment they appreciate having the games because they feel good about the way they're playing. Against Sydney they were really up for it because they felt as though they had a win in them and the attitude has been so good. So I don't think they're worried about the backlog.''
Wellington's next game is against the winless Melbourne Heart across the Tasman on Friday night.
Meanwhile, midfielder Carlos Hernandez's family has arrived in Wellington following a protracted process to arrange visas and passports for his partner and children.
There had been speculation Hernandez was unhappy with the club as their arrival had been delayed due to the paperwork and logistics involved but they touched down in the capital this morning.