British and Irish Lions captaincy contender Caelan Doris requires a shoulder operation ahead of their tour to Australia.

The Leinster captain, widely considered to be a frontrunner to skipper the Lions this summer, picked up a shoulder injury in Saturday’s game against Northampton Saints, and the full extent of it remains unknown.

Lions head coach Andy Farrell is due to name his squad for the series on Thursday afternoon, live on Sky Sports.

Back-rower Doris, who scored a try in his province’s 37-34 Investec Champions Cup semi-final defeat by Northampton on Saturday, has been ruled out of next weekend’s United Rugby Championship clash at home to Zebre.

Doris and England lock Maro Itoje have been tipped as contenders to captain the Lions.

A short update from Leinster read: “Caelan Doris will have a procedure this week on a shoulder injury and a further assessment will be carried out afterwards.”

Farrell’s Lions begin their three-match Test series against the Wallabies on Saturday July 19 in Brisbane before playing in Melbourne a week later and finishing in Sydney on August 2.

Owen Farrell’s hopes of being selected for the Lions tour were also dealt a blow after he suffered a head injury during Racing 92’s 29-15 Challenge Cup semi-final defeat by Lyon.

Farrell, selected at inside-centre for the first time this season instead of his usual fly-half position, was forced off after just 19 minutes with the score at 0-0.

The 33-year-old England fly-half took a hit to the head from Mickael Guillard’s hip as he attempted to tackle his opponent.

Farrell is a three-time Lions tourist and was in contention for a place in father Andy’s squad for this summer even though his debut season at Racing 92 has been affected by a groin injury.

The Lions squad announcement will be streamed on the Sky Sports App on Thursday May 8 from 2pm with live coverage on Sky Sports Mix and Sky Sports Main Event. All games in the British and Irish Lions tour this summer will be live on Sky Sports.