Johnny Sexton a major doubt for Ireland's Six Nations campaign

INJURY: Jarrad Butler of Connacht is tackled by Jonathan Sexton of Leinster. Sexton has undergone a procedure on an injured cheekbone. Pic: Harry Murphy/Sportsfile

Ireland captain Johnny Sexton is a major doubt for the Six Nations after undergoing a procedure on a cheekbone injury sustained against Connacht in the URC last Saturday.

Sexton, who was making his first start since Ireland took on South Africa in November, sustained the facial injury while tackling Connacht's Jarrad Butler and was substituted.