Trent Boult acknowledged the short-term outlook is not promising for Ross Taylor after the New Zealand batsman suffered a calf injury on day two of the first Test with South Africa.
The Black Caps enjoyed the better of Thursday's play in Dunedin, restricting their opponents to 308 all out before reaching 177-3 in reply, thanks largely to skipper Kane Williamson (78 not out) and Jeet Raval (52).
However, there was a potentially troubling blow for the hosts when Taylor hurt his right calf and retired on eight, the 33-year-old in clear discomfort as he was helped from the field by New Zealand's physio.
"He looks pretty disappointed, as we can all understand," seamer Boult was quoted as saying by stuff.co.nz.
"The way he walked off, it doesn't look too good, but we'll see how he pulls up tomorrow [Friday]."
Boult returned admirable figures of 4-64 from 32.4 overs as New Zealand made light work of South Africa's lower order on Thursday, and is hoping his side can build on an encouraging display with the ball.
"It's nicely balanced and still a lot of good quality in the changing room that will look to cash in," he added.
"We've got to look to keep them out there as long as possible. We know the first hour will produce a bit of movement sideways off the wicket, and the plan is to keep them out there, build a big first-innings lead and have a crack at them with the new ball."