Jordan started on the right wing in last week's 26-10 defeat at Mbombela Stadium but he barely featured - not touching the ball in the first half and making one break in the second after an Ardie Savea assist.
After the All Blacks transferred from Mbombela to Johannesburg, Jordan began feeling unwell on Monday local time and has not joined the team at training on Tuesday; leaving him in major doubt for the second test at Ellis Park.
With Jordie Barrett also under an ankle injury cloud after he left the field in the second half in Mbombela, Jordan was the leading candidate to start his first test for the All Blacks at fullback.
The All Blacks may now be forced to further reshape their back three with Beauden Barrett, provided he fully recovers from the ugly fall onto his neck, or David Havili possibilities to start at fullback.
