Johnny Sexton faces a battle to be fit for Ireland's Six Nations opener against Scotland.
The fly-half suffered a knee injury during Leinster's European Champions Cup victory over Northampton Saints at Franklin's Gardens last weekend.
Leinster head coach Leo Cullen is unsure how long his captain will be sidelined but is hopeful he will be ready to face Scotland at the Aviva Stadium in Andy Farrell's first game in charge on February 1.
"You would love if he was back [to play for Leinster before the Six Nations], but it's probably more realistic for Ireland," Cullen said.
"He's seeing somebody in the UK and he'll go back there just to get an update in a couple of weeks.
"He's working hard to try and get himself back as quickly as possible, but he won't be a million miles away [for the start of the Six Nations] hopefully."
Scott Fardy will skipper Leinster in the absence of Sexton in the return fixture against Northampton in Dublin on Saturday.
The Pro14 champions, runners-up in Europe's premier club competition last season, are top of Pool 1 with three wins out of three.
