Sixth-placed City are now eight points clear of the reigning champions, who do have a game in hand on their direct rivals, one of five matches remaining for the Queensland club.
Adelaide United, considered a legitimate title challenger, are now just four points ahead of City prior to their match away to Wellington Phoenix on Sunday.
But Van 't Schip brushed aside claims his team could now have the Reds in their sights over the final four rounds of the campaign.
"First we have to make sure we get into the playoffs," he said.
"That's not sure at all. We have four tough games ahead of us. Until the end we have to be really prepared.
"Everybody knows it was very important, a six-pointer. Now there's a gap and we have to make sure that we continue gaining points and make it difficult for Brisbane to catch us. And maybe you can even look a little more up (the table)."
Marquee striker Josh Kennedy returned to the City starting XI but was withdrawn after 55 minutes.
According to Van 't Schip, the veteran centre-forward was taken off as a precaution, with the energy of his replacement, former Roar midfielder Massimo Murdocca, needed to keep the pressure on the visitors.
"Josh didn't train (until) the last few days," he said.
"Knowing that we have four more games to come and knowing we have problems pressing - we needed a little more power and legs up front.
"We know he can play 90 minutes, that's what we want to build up to again."
City also lost James Brown, scorer of the only goal in a 1-0 win away to Sydney FC last Friday, to an ankle problem in the first half at AAMI Park.
The injury plagued former Newcastle Jet and Gold Coast United player will undergo scans to determine to extent of the issue.
Harry Novillo proved to be an energetic and willing replacement, although Van 't Schip hopes the Lyon academy graduate can sharpen up his decision-making in the final third during the coming weeks.
"He brings something different, but also he has to get a little bit more used to the way we want to play," the Dutchman said.
"His final pass was maybe a bit hard on one or two occasions. Hopefully for the next game he can be closer to starting."