The 31-year-old number eight will be assessed by the Blues medical team on Friday to confirm how much of the new season Rush will miss.
Talisman Rush was a key member of the Blues side that qualified for the Heineken Cup quarter-finals last term. and was inspirational as the Blues finished in second place in the Magners League last season.
The former All Black has torn the cartliage from the back of his knee cap and will go under the surgeon’s knife on Wednesday.
