The local businessman admitted that he has queried purchases in the past - namely the signing of Peter Crouch for £10 million in 2011 from Tottenham - but has always been supportive of Pulis’ vision.
Stoke are 4/5 to finish in the top 10 of the Premier League with Coral
Crouch had recently turned 30 when he joined the Britannia Stadium outfit and has since gone on to score 20 goals in 67 appearances for the club, but Coates was wary of the limited re-sale value of the striker.
"I never liked that [Crouch] deal financially, but I did that to support the manager," Coates told the Daily Mirror.
"I did question the deal financially because it was a lot of money.
"If you buy a player at the latter end of his career it's clearly more difficult to get your money back, but no player will come into the club or go without Tony's approval. That's crystal clear and he may be one of the few managers in that position."