Booy revealed last week that a joint bid for the pair - thought to be around 10million euros - from PSV had been turned down.
PSV looked resigned to missing out on the duo, with sporting director Marcel Brands saying: "Utrecht asks too much for us. They're too expensive."
However, dialogue between the two Eredivisie clubs has remained open and Booy can understand why the players' heads have been turned.
"We have indicated where our valuation lies," he said in De Telegraaf.
"PSV were given the weekend to go and consider this.
"I understand that the players are positive about a transfer because they can improve. For us, it is an important balance between the sporting and financial story."
Another stumbling block - along with the fee - could be the fact Utrecht want Strootman and Mertens to be seen in isolation and therefore negotiated separately, but PSV want the pair.
"They have indicated they are only interested in a 'package deal'," Booy added.