"I left him out after the Spain game but his reaction has been very good. He's playing very well.
"He was man-of-the-match in Chelsea's opening clash with Birmingham and he's looking like the Shaun Wright-Phillips that we know. When he's playing like he has been, there's no one trickier or quicker in the game."
It hasn't always been plain sailing for the 25-year-old Phillips since he moved back south from Manchester City.
In his first season at Stamford Bridge, he was a bit-part player in Mourinho's team as he struggled to adjust to the pressure of playing for a club with Chelsea's profile and greater competition for places.
"Moving from a club without the same conditions, responsibility and without the pressure is always a question mark for any player," said McClaren.
"The first season at Chelsea was not easy for Shaun but the second season he made a big improvement. His choices on the pitch and the way he thinks about the game are much better. Some players, after one season, they don't resist and they want to leave but the lad has always believed in himself."