BIG BLOW: Kieran Read missed All Blacks training today and is in doubt for Sunday's test against the Pumas in La Plata.

No 8 Kieran Read missed All Blacks training today and is in doubt for Sunday's test against the Pumas in La Plata.

Stand-in captain Read remained at the team hotel and is thought to be unwell. The next 12 hours will be crucial to his recovery.

Liam Messam ran at No 8 and Steven Luatua came into the starting blindside flanker role during today's training at Saint George's School in Buenos Aires.

If Read, a world class no 8, is ruled out, hooker Dane Coles is likely to come onto the bench and provide cover for the thin loose forwards.

Experienced centre Conrad Smith is favoured to assume the captaincy with hooker Andrew Hore another leadership option.

Richie McCaw ran freely today but it is highly unlikely he will be rushed onto the bench while still recovering from a medial ligament knee injury.

If the All Blacks require additional cover next week Bay of Plenty's Tanerau Latimer would be called in after Canterbury's Matt Todd had surgery.

An update on Read's fitness is expected tomorrow.