Johnny Sexton has emerged as a doubt for the Six Nations after suffering a knee injury in Leinster's 43-16 win over Northampton in the Heineken Champions Cup on Saturday.
The Leinster and Ireland number 10 was taken off early on in the second half during the win at Franklin's Gardens.
The Blues captain had extended and twisted his knee in a somewhat late tackle by Northampton centre Matt Proctor.
Head coach Leo Cullen said after the game that he will have a scan on Sunday and a full update will be given on his fitness at a media briefing on Monday (today).
Sexton has been tipped by many to replace Rory Best as Ireland Captain and this will cause new head coach Andy Farrell a headache if he can't call upon the 34-year-old come the Spring with their opening game against Scotland in Dublin just eight weeks away.
Leo Cullen confirms Johnny Sexton has a knee injury, proper update Monday after it's assessed tomorrow
— Rúaidhrí O'Connor (@RuaidhriOC) December 7, 2019
Leinster must now prepare to face Northampton again as they welcome them to the Aviva Stadium on Saturday 14 December.
They then have three PRO14 derbies in two weeks before lining out for more European action in the New Year.
Leinster's other outhalves are Ross Byrne, his brother Harry and Ciaran Frawley. Neither of the latter have made their European debuts yet.
Leo Cullen spoke about them after the game on Saturday, saying that "the two of them are progressing well."
The boss seemed enthusiastic about possibly playing them if necessary.
"They're only 20 and 22 so they are just trying to add little bits of experience.
"Frawls was unlucky to get injured over here in pre-season and be out for a decent chunk. But those guys are training well."
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