Last updated on .From the section Irish Rugby

McGrath was helped off the pitch during Leinster's European Champions Cup win over Toulouse on Saturday

Ireland scrum-half Luke McGrath will miss the Six Nations after being ruled out for up to eight weeks with a knee ligament injury.

The Leinster man hobbled off during the province's 29-13 win over Toulouse on Saturday.

Scrum-halves John Cooney and Kieran Marmion are also currently nursing injuries but could return in time for the tournament opener.

Ireland host England on 2 February in their opening game.

Johnny Sexton also remains sidelined and will play no part in Leinster's final European Champions Cup pool game against Wasps on Sunday.

The recently crowned World Rugby player of the year continues to recover from a knee tendon injury that ruled him out of the Toulouse game.

McGrath featured in all four of Ireland's autumn internationals, making three appearances from the bench.

With established first choice scrum-half Conor Murray missing through injury, Connacht's Marmion was Joe Schmidt's preferred option at nine for the wins over Argentina and New Zealand.

Marmion is in a race to be fit for the tournament having been out of action since November with an angle injury sustained during the All Blacks game.

Ulster's Cooney was a late withdrawal from Saturday's Champions Cup win over Racing 92 having failed a fitness test and is a doubt for the province's crucial encounter with Leicester this week.

The fitness of Marmion and Cooney will no doubt impact who is selected to understudy Murray against England.

In better news for Schmidt, Leinster quartet Devin Toner, Dan Leavy, Sean O'Brien and Robbie Henshaw have all returned to full training.

The head coach, who will leave his role following the World Cup in Japan, is expected to name his Six Nations squad on Wednesday.