The Swans sealed the first major trophy win in their history back in February but have won just one of their five top-flight fixtures since.
But the Dutchman believes Saturday's 2-2 draw with Norwich proves that his team-mates have no plans to ease up.
He told Wales Online: “If that was the case we would not have come back [to earn a point]/
|6/4||Swansea are 6/4 to finish in the Premier League bottom half with BetVictor|
“So to show the fighting spirit, combined with good football, we can get the points to have a good end to the season.
“But we have to make sure we are on it."
With Michael Laudrup's side currently ninth in the league on 41 points, the 29-year-old is targeting an improvement on last season's 11th-placed finish.
“It would almost be like winning the league finishing eighth,” he continued.
“Look at where we came from. Two years even I admit I didn’t know too much about Swansea, and I think that was the same for a lot of people.
“Last year we had good credit and recognition but there always seemed to be a ‘but’ about us and questions if we could do it for a second year.
“We are still ninth and we have it in our own hands to make that step.
“We have a better squad and group of players than last year, we need to show that and you do that by finishing higher than last year.
“The most important thing for us is to stay in the top 10. We have some tough games to come but we have it in our own hands to at least finish top half.
“Norwich away is very tough and where a lot of teams lose, so to get one point – our first against them – has to be a good point."