The New Zealanders have lost four of their past six matches after starting the season well leaving Ifill lost as to why things have turned for the worse.
"I don't think any of us, bar Manny Muscat, have been consistent enough and I really don't know why," Ifill said.
"We're here every day working hard trying to fix things and it just doesn't seem to be working come the weekend.
"I don't think we can train any harder or any longer. I really can't put my finger on it. It's frustrating at the moment.
“I don't think the players have been playing well enough to stay in the team and I include myself in that.
"It's been tough and it's been pretty tough for (coach) Ricki (Herbert) because he doesn't know what his best XI is because there are a lot of us who've not stepped up.
"I don't think anybody can say they've played anywhere near the level they did last season and that must be frustrating for him and obviously makes his job a lot harder."