Netherlands are third in Group C, three points behind second-placed Northern Ireland but with a game in hand ahead of the sides' clash on Thursday.
But the former Southampton and Everton boss warned that beating Northern Ireland - who won four consecutive qualifying matches before their 2-0 defeat at home to Germany in September - would not come easily.
"They are fighting machines," Koeman told reporters of their opponents.
"Perhaps they haven't got the structure or quality technically but it's very direct, direct confrontations. They are a team that can make the games difficult for any opponent and we have to see how we can find the solutions. If they can get at you, they will, and they will get you by the throat. You've got to be prepared for that.
"It can be that home and away there is a difference in their game. I think they had the idea to perhaps try to finish Germany off and, for an hour, they were able to live with them and had the better opportunities.
"But from the moment they went 1-0 down, you can see the spaces increase and the Germans took advantage."
Defeat in Rotterdam would leave Netherlands six points behind Northern Ireland and Koeman admitted his side are under pressure to deliver a result before winning again in Belfast in November.
The Oranje lost 3-2 at home to Germany in their most recent qualifier on home turf in March, but Koeman backed the likes of Liverpool's Virgil van Dijk and Barcelona's Frenkie de Jong to cope with the high-stakes scenario.
"We still have to qualify," said Koeman. "Now we play both games against Northern Ireland for our ticket. It starts [on Thursday] and if we don't get the result we want, it will be very painful.
"There is always pressure for Holland. We think that we've always got to play everywhere, and we've got the quality for that. I think that this team is very hungry.
"Not many players have played in the big tournaments and everyone wants to be there but there is always the development of a team.
"These two games against Northern Ireland are really important. There is pressure but the players are used to that - they play for big clubs and they've got to win so it's no different to that."