The 19-year-old midfielder has followed fellow academy products Sam Byram, Lewis Cook, Alex Mowatt and Charlie Taylor into the first-team squad and made his first appearance of the season in Sunday’s goalless draw at Reading.
“He is the one throughout the whole year I see as big potential to develop and get more playing time,” said Rosler.
“At the moment he’s benefiting from the suspension of Cooky and the injuries to Luke Murphy and Tomasso Bianchi, but he’s using his chance and earning my trust by giving me the performance he did against Reading.
“I felt I can trust him, I can play him and he won’t let himself or the team or myself down and for such a young player like him that’s a big compliment.”
Phillips made his debut at Wolves towards the end of last season under former boss Neil Redfearn and scored his first senior goal in the following game against Cardiff.
“We will not do any players a favour when we put them in at the deep end, living or dying,” Rosler added.
“There are certain periods when we can allow players with limited experience, to throw them in and see for one or two games how they cope.
“Kalvin coped very well in my opinion. He raised himself up to the level, to the tempo and intensity.
“I already saw in pre-season when we used him continuously against Hoffenheim and Frankfurt.
“So when everybody’s fit, I don’t think Kal will play week in week out, but he’s always pushing and will always put pressure on the established players.”