Ryan will have further scans to find out if his anterior ligaments are also damaged – but the result is that he out of rugby for the immediate future.
Highlanders’ coach Greg Cooper will be hoping injuries to other key members in his squad will be less serious to that of Ryan’s.
Stand-in Highlanders captain Craig Newby suffered a haemotoma to his quadriceps, Jimmy Cowan a tight hamstring and prop Clarke Dermody left the field near the end with a shoulder injury against the Chiefs.
Ryan, who has been one of the form players in the Highlanders squad this season, will be a massive loss to the men from Dunedin and his injury will make it difficult for him to force his way into the All Black squad once the international season begins.
Troy Flavell, Greg Rawlinson and Ali Williams are all in top form for the Blues while Jason Eaton has also made his return to action after sitting out with the All Black conditioning squad.
With Chris Jack also out with an injury this might see one or two spots open up in the All Black squad in the second row.