The Dutch coach is questioning how they will react to the defeat to Liverpool.
“When you are in the driver’s seat and someone else is coming, you can get a little bit nervous,” said Hiddink.
“If it was just four points it would be very close, but they have that game in hand. But it’s clear that after Saturday’s unexpected result the tension has come back.
“If we want to track them, we have to keep on winning. That’ll give tension to the end of the season, which is good for everyone.
“Every now and then you get a defeat you don’t expect. Sometimes you don’t expect it at home because you have a beautiful record there.
“But they’re a very experienced team. Let’s see how they react in the upcoming days.”