Pulis has come in for criticism from some fans after seeing Stoke win just once in their last 11 Premier League games.
Saturday's goalless draw at home to West Brom ended a run of three straight defeats and Cameron insists the spirit in the squad remains positive despite their poor run of form.
"Losing to Newcastle with that late goal was a big dagger to us," Cameron told The Sun.
"Most teams would put their heads down and not come back from that but we showed we still have a positive attitude.
"The players are behind the manager 100 per cent.
"We were flying around Christmas. We beat Liverpool at home and everyone was on cloud nine.
"You get these bad bounces and there's no sense in being negative."