He caused a minor stir over the weekend by appearing to question the club record £10m signing of Crouch 18 months ago.
But Coates says: "I did question the deal financially because it was a lot of money. If you buy a player at the later end of his career it's quite clearly more difficult to get your money back.
"But the manager wanted him and I did it for the manager - and at no time was it a criticism of the player."
Coates also said Crouch's experience had its place at Stoke because there remained a balance to be had between older players and younger potential like deadline-day signing Jack Butland.
"We want a balanced squad, as does the manager, because a good squad is made up of experience and younger promise, so we are certainly not saying we won't buy experienced players in the future," he explained.
"The ultimate objective is to remain in the Premier League and you need a good squad, made up of youth and experience, to do that."