Super Rugby: All Blacks assistant coach Ian Foster leaves door open for Ma'a Nonu World Cup call-up

All Blacks assistant coach Ian Foster has left the door open for Ma'a Nonu to make the World Cup squad.

The 36-year-old Nonu has been in hot form of late, showing glimpses of his old storming self throughout the season.

Despite not being named in the 41 players announced for the All Blacks foundation day squad, injuries to the likes of teammate Sonny Bill Williams and the ever competitive nature of the Super Rugby season still leaves Nonu's dream of making the plane to Japan very much alive.

Speaking to Newstalk ZB's Martin Devlin, Foster said Nonu's age is not a factor and insisted that it will be his performances on the field that will be the thing that he will be judged on.

"Age has never been a barrier," Foster said. "He like everyone has just got to keep showing that his hunger levels are right and his skill levels are right. It's a pretty competitive position in the midfield.

"But I think regardless of whether he makes a return to the All Blacks, hasn't he done himself proud the way he has played."

Foster was full of praise for Nonu's return to New Zealand and the form that he has rediscovered, and didn't rule out the possibility of a stunning return to the national side.

"It's going to be a challenge for him week in week out and I guess that's a factor that we bring into play but I mean there won't be too many players at the World Cup who'll play all seven games.

"[But] you never say never and I just have massive respect for the way he's come back and put himself out there because he's been a player that has taken a bit of flack around the franchises at times and he would've been susceptible to that to if he hadn't played up to his top level.

"So I think he's doing himself proud and certainly reflecting a pretty confident Blues environment at the moment."

The Blues will hope to extend their winning streak against the Chiefs in Hamilton tonight.