Pulis has been charged with improperconduct by the FA following his criticism of referee Lee Probert after last month's 2-1 Carling Cup defeat to Liverpool at the Britannia Stadium.
Charged: Stoke boss Tony Pulis
The Welshman questioned Probert's decision to disallow a Jon Walters effort in the first half of the game and felt there had been a foul on Peter Crouch which should have seen Stoke awarded a penalty.
He was also unhappy that a Jamie Carragher tackle on Matthew Etherington did not result in a red card, and told the BBC: 'You have to have a level playing field - you can't have it both ways, and he (Probert) has done that in my opinion.
'He has not made the correct decisions.'
Pulis went on to refer to past Potters matches where he thought Probert had made poor decisions.
He has denied the FA charge, requesting a personal hearing, and the 56-year-old has the full support of Coates, who feels Pulis' words were justified.
'I am surprised and disappointed because Tony made legitimate points about poor decisions,' said Coates, quoted in The Sentinel.
'I think managers are entitled to question poor decisions. I'm not saying referees can't make mistakes - we all do.
'But why shouldn't referees be criticised? Why should they be wrapped in cotton wool?'
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