Sexton a doubt and Henshaw is out
Leo Cullen's problem has now become Joe Schmidt's problem as Robbie Henshaw is a serious doubt for Ireland's Six Nations opener against England on February 2.
Originally, the Athlone centre had been assigned roughly a one-month recovery period after straining his hamstring prior to Ireland's November international against Argentina.
One month later, Leinster confirmed Henshaw's problem is more serious than first suggested, adding eight weeks to the time frame.
Already, Leinster will have to make do without their primary inside centre for the second-half of the pool phase of the Champions Cup and two inter-provincials over the Christmas period.
"Obviously it is a huge hole to fill," stated senior coach Stuart Lancaster.
"That, alongside Joe Tomane, being out for a longer period of time, your two physical centres who would bring that balance to your back line."
It doesn't end there for the Blues, as Jonathan Sexton is still considered a serious doubt for the return leg with Bath in Europe at the Aviva Stadium on Saturday night (Live BT Sport 2, KO 5.30).
"We're optimistic, hopeful, but you couldn't say for definite at the moment," revealed Lancaster.
"He got a bang on his calf, which has meant that he is going to be limited as to what he can do at the start of the week.
"We will give him as long a time as possible to get himself available."
In all likelihood, Ross Byrne would do more than an adequate job at out-half.
Lancaster said of Sexton's deputy: "He played well in the November internationals when he got his opportunity.
"I thought he was excellent against the Dragons, one of the best performances I have seen him play. He is certainly confident and ready to go if Johnny is not."
Numbers eight Jack Conan must be confident of starting on Saturday, after coming through against Bath, as did Dan Leavy, Jordan Larmour and Rory O'Loughlin.