The centre damaged an ankle during the All Blacks' Tri-Nations defeat in South Africa last weekend, and the knock will be tested in training before the announcement.
Henry rates the Wellington man's chances as 50-50, although Umaga himself is confident he will be ready to play.
Umaga's absence would mean a second gap to be filled in the XV, after half-back Byron Kelleher was ruled out through concussion.
Leon MacDonald, who started at full-back in Cape Town, is a likely candidate to step into the skipper's shoes.
However, such a move would give the Canterbury utility back an uncomfortable feeling of deja vu.
MacDonald replaced Umaga in the three-quarter line in his last outing against the Wallabies - the 2003 World Cup semi-final defeat.
"Not pleasant memories," MacDonald told the Dominion Post. "I remember the confidence, the way they played the game.
"We felt we played really well at the start and then you could feel their confidence growing. Their demeanour on the field changed, especially in the last five minutes.
"Memories like that, you keep fresh in the back of the mind so you never go into a game like this complacent."
Prop Greg Somerville also recalled the bitter reverse, which came only months after the All Blacks had thrashed their rivals 50-21 in Sydney.
And it was the former which also proved to be his motivation.
"The country was writing them off and everyone was against them (in 2003) but they came out and showed how capable they are," he said.
"It's probably the same this week, people have been getting into them and questioning them. That'll probably steel them together and make them pretty tough opposition this weekend."