Leinster have confirmed that Ireland international Jack Conan has suffered a shoulder injury, casting fresh doubt over the province’s back-row resources after Caelan Doris was already ruled out with a long-term foot and knee issue.

Conan was injured while scoring a crucial second-half try during Leinster’s impressive 48-23 Investec Champions Cup Round 1 victory over Clermont ASM at Stade Marcel-Michelin.

The experienced British & Irish Lions No.8 powered through two French defenders just after a restart to score a momentum-shifting try that effectively ended any hopes of a Clermont comeback.

The timing of the setback is far from ideal for both Leinster and Ireland.

With Doris sidelined, Conan had become the leading candidate to shoulder much of the workload in the No.8 jersey over the coming months. The 33-year-old is a key figure for both club and country and any prolonged absence would leave Leo Cullen  – and, for that matter, Ireland head coach Andy Farrell – with a significant hole to fill heading into a demanding period of domestic and European fixtures.

In their latest squad update, Leinster stopped short of putting a timeframe on the injury but confirmed further assessment is required.

“Jack Conan sustained a shoulder injury in the EPCR game v Clermont Auvergne and will require further assessment.”

The province also revealed that Jordan Larmour will require further assessment on a calf issue, while Hugh Cooney suffered a hand injury in the A game against Edinburgh.

Andrew Osborne also suffered a head injury in the same A game, while there was no further update on “Harry Byrne (concussion), Jack Boyle (achilles), RG Snyman (knee), Caelan Doris (foot and knee), Paddy McCarthy (foot), [or] Diarmaid Mangan (foot)”

Conan’s injury provided the only sour note on an otherwise highly successful European opener for Leinster, who recovered from a 16-15 half-time deficit to score 33 second-half points and secure a bonus-point win on French soil.

Leinster face Munster in the URC this coming weekend at the Aviva Stadium.