Johnny Sexton could be a doubt for the Six Nations.
The Leinster outhalf suffered a knee injury in Leinster's win over Northampton in the Champions Cup on Saturday, following a tackle from Northampton centre Matt Proctor.
Footage of Johnny Sexton’s knee injury yesterday.
Does not look good for the Ireland international. pic.twitter.com/hCFDPkBvuA— RugbyLAD (@RugbyLAD7) December 8, 2019