Matt Todd trains with New Zealand

Crusaders flanker Matt Todd has been training with the All Blacks this week, fuelling fears that captain Richie McCaw may not be fit enough for their semi-final against Australia on Sunday.

McCaw has struggled throughout the tournament with a foot injury, which caused him to miss matches against Japan and Canada in the pool stage.

Todd is reportedly on stand-by to replace McCaw, after the captain could only manage light training today (Wednesday).