The 31-year-old number eight is due to undergo an assessment by the Blues medical team tomorrow (Friday) before it will be announced how much of the upcoming season Rush will be forced to sit out.
The talisman was an integral part of the Blues side which made it through to the Heineken Cup quarter-finals and into runners-up spot in the Magners League last season, and he will be sorely missed in the initial games.
Arms Park coach Dai Young has a tough decision to make given the Kiwi ace's absence, although it is likely he will turn to either Mark Lewis or Andy Powell to replace Rush until his return.



