Sean Jansen ruled out of Ireland's autumn series with knee injury

Sean Jansen will miss the rest of Ireland's Nations Championship campaign after a knee injury forced him off during the 42-12 win over Argentina in Dublin. The BBC reports that the Connacht forward will return to his province to continue his rehabilitation.

Jansen had started at number eight, the forward who packs down at the back of the scrum and usually picks up the ball and drives it forward. He was there because Caelan Doris was absent. Doris and Jack Conan were already injured, which left head coach Andy Farrell with few options in that position.

Dan Sheehan has also been hit hard. The hooker picked up a concussion, a blow to the head that disrupts how the brain works, against Argentina. He will miss Ireland's home match against Fiji. He is a doubt for the game against South Africa on 21 November, because he has to work through a 12-day return-to-play protocol, a set of graded steps a player must pass before going back into contact. Sheehan had been Ireland's captain in Doris's absence, so there is a leadership gap to fill as well as a playing one.

Farrell has moved to bolster the squad. Uncapped Ulster forward David McCann has been called up amid the back-row problems, and Gus McCarthy has joined to add cover in the hooker position. The hooker strikes for the ball in the scrum and throws it in at lineouts, so depth there matters.

Both McCann and McCarthy were originally named in the Ireland XV squad for the fixture against Fiji 'A' in Cork on 20 November. Tom Ahern, Ethan McIlroy and Michael Milne have been ruled out of that match.

There is some better news in the backs. Bundee Aki missed the Argentina game through illness, but he is expected to resume full training on Tuesday.

Ireland's November programme is Argentina, Fiji and South Africa. The Argentina match is done and dusted with a comfortable win, and the next big test is South Africa on 21 November. Whether Sheehan is fit for it will decide a lot about how Farrell builds his team, and how many of the new faces get a chance to play.