Sexton in race for Six Nations
Johnny Sexton is in a race to be fit for the start of Ireland's Six Nations campaign due to the knee injury he picked up in last Saturday's win over Northampton.
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The out-half underwent an initial scan on Sunday and after it failed to determine the full extent of the problem, Sexton was sent to see a specialist yesterday.
Sexton has been ruled out of this weekend's return game against Northampton at the Aviva Stadium with Ross Byrne set to start.
Leinster will know more over the coming days, but it is understood it could be several weeks amidst fears that Sexton significantly damaged the ligaments in his knee.
Should the 34-year-old miss any of the Six Nations, it would be a blow to new head coach Andy Farrell as he also has concerns over Joey Carbery (ankle), who hasn't played since the World Cup, but is hoping to return for Munster over the festive period.
With Jack Carty struggling for form, the door would reopen for Byrne, who missed out on selection for Japan.