Adelaide United triumphed 3-2 over the Heart at Hindmarsh Stadium on Friday night, a result which left the new club without a win from three games.
Two losses and a draw for the Heart have sapped their confidence, van 't Schip says.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Of course the results are important, it's going to take time but there are things that we have to improve," he said.
"As a team we also have to be more eager to get a result, and that is something that has to get into the team.
"It's only three games gone, but when you are not getting points it's not good for the confidence ... so even if we are a new club and a new team, you need that.
"And that is something we have to work hard on, to get our first result."
Heart's performance against the Reds was full of merit, twice coming back from being a goal behind to square the scores, but some basic blunders proved costly.
Reds winger Iain Ramsay's two goals, including his 88th-minute match winner, were decisive and had van 't Schip lamenting their "giving away" of goals.
His sentiments were echoed by experienced defender Simon Colosimo, who was frustrated at the ease Adelaide scored.
"We are playing some good football but playing good football and giving goals away won't get you results," Colosimo said.
"We had to work ever so hard to score our goals ... and take nothing away from Adelaide, but we have made it a little bit easier for them.
"And at this level, as a team and as individuals, we can't afford to do that.
"It was one of those games that we are going to look back at as a group and know that we gave too much away.
"The game plan was right, I just don't think defensively it was executed."
Melbourne returns to home turf to host Perth Glory next Sunday, while Adelaide, now with one win and two draws to open their season, travels to meet North Queensland next Saturday.
