Ireland's Sexton a Six Nations doubt due to cheekbone injury

Ireland could be without skipper Johnny Sexton for the start of their Six Nations campaign next month after his club Leinster said he had to undergo a procedure on a cheekbone injury.

Sexton was forced to leave the field after colliding with Connacht's Jared Butler in Leinster's 41-12 victory on Sunday.

Leinster said he would be assessed after having the procedure on Tuesday. Ireland begin their Six Nations campaign against Wales in Cardiff on Feb. 4 before taking on defending champions France in Dublin a week later.

Flyhalf Sexton, 37, has said he is planning to retire after the World Cup in France this year.