Josh van der Flier's dream year has ended in a nightmare scenario as the flanker has been ruled out for the rest of the season.
The IRUPA Young Player of the Year suffered a high ankle damage (syndesmosis) against Ulster and saw a specialist on Monday.
A review of his injury led to an operation on Tuesday to repair the damage with an estimated recovery length of eight weeks.
This means the openside will miss out on Leinster's assault on the PRO12 play-offs and on what would have been his first Ireland tour to South Africa.
The unavailability of Van der Flier and the uncertainty over Sean O'Brien's slow-healing hamstring could lead to the rejuvenation of Jordi Murphy's season. The multi-purpose back rower has been able to find his form of late.
The 25 year-old took more time than most to get over the World Cup hangover and has repaid the faith of coach Leo Cullen with a strong close to the season.
In further news, Rob Kearney (ankle) and Jonathan Sexton (quad) are making significant headway as they target a return against Ulster in the PRO12 League semi-final on Friday week.
As always, Ian Madigan will be on standby for Sexton in what could be a surprising late chance to leave Leinster for Bordeaux-Belges on a winning note, rather than see the season fade away.
Kearney is well-covered by the international class back-up of club captain Isa Nacewa and Springbok Zane Kirchner.
However, the competitive instinct of both Ireland senior internationals has kicked in as they do everything within their power to regain full fitness.
Afterall, Kearney has played just six times in the PRO12 this season, completing 80 minutes just twice.
Sexton hasn't fared much better, starting and finishing just one of his eight appearances.