The 20-year-old midfielder joined the League One club on a season-long loan deal in the summer and has since gone on to become an ever-present figure in the Portsmouth midfield.
In what is his second temporary spell away from his parent club, Robertson is already making his presence felt at a Portsmouth side who are flying in League One.
The player on his part insists that it has all been a learning experience for him having arrived at the club with an open mind.
“We should come into it [loan spells] with an open mind”, Robertson told the BBC while giving his opinion on some of the Premier League loanees not looking at spells in the lower leagues as learning experiences.
“I do that with everything I do in life.
“The gaffer’s great, the boys are really great, the coaching staff are great. It’s just nice. There is a lot to learn.
“But as you said about some of the boys they might not have the right mind, they might not look at it the right way but it is just a bit different for me.
“I just like to look at things with an open mind.”
Manchester City will be keeping a close eye on how Robertson deals with the slog of a League One season.