The Southampton boss is clearly a fan of his Dutch compatriot.
The Dutch national team will not be at Euro 2016 this summer as the team is currently struggling to transition from the Louis van Gaal years.
One area of the pitch in which they are particularly struggling is up front.
The likes of Klaas Jan Huntelaar and Robin van Persie are no longer young enough to carry the team whilst Luuk De Jong and Bas Dost still have their doubters.
But there is a new man on the scene, Vincent Janssen.
The AZ Alkmaar striker has scored 27 goals in the Eredivisie this season and scored on his Holland debut against England recently.
"He played (v England) against strong defenders from the Premier League. What pleased me most was the fact that he immediately grabbed the ball when the Dutch team got a penalty. You should still do, but at that moment and that action showed he has the necessary self-confidence.
"If you are scoring 27 in the Eredivisie, that's very good. Only you do not know what these goals are worth at the highest level. That's something we have to wait and see.
“Now Van Persie and Huntelaar are not there, it seems to me that Janssen will get the chance to see over time whether he would indeed be the striker for the Dutch national team. "
So should he bring him to Southampton?
On the one hand it is a no-brainer. Janssen is a top striker who would fit in brilliantly at Southampton ahead of a hectic 2016-17 schedule.
It could however depend on the future of Graziano Pelle. He has been linked with a move away from the club leaving Southampton short up front.
Janssen would then be the perfect option and Koeman is clearly a fan.
So maybe this is one to keep your eye on.