The Canterbury ace's inspirational form at second five-eighth has been one of the cornerstones of coach Graham Henry's game plan.
However, a broken leg has left the 23-year-old out of action for two months and the position is now open for one of a number of competitors to ascend to the pivot role.
And that has had knock-on effects for other positions in the first XV and the squad.
Henry told the New Zealand Herald: "Hopefully it is only a six-week injury, but there is no guarantee of that.
"However, if he recovers and Canterbury stay true to form and get through to the latter stages of the NPC, then Daniel should be able to get some matches in before the All Blacks tour."
Henry and his staff will now use the National Provincial Championship as a testing ground for the various contenders.
Goalkicking utility backs Luke McAlister and Leon MacDonald, who started the Bledisloe Cup win over Australia last weekend on the bench, are the leading contenders.
Aaron Mauger may also be considered, but Henry admitted he would cast his net wider than the current Tri-Nations party.
The ex-Wales and British & Irish Lions boss said: "We may also look at someone else who is not such an obvious choice but I am not going to discuss that.
"We will have to spend a fair bit of time during this week talking it through.
"But McAlister could go there, although we tend to think he might be better one place further out, while MacDonald was going to play there in the third Test against the Lions until he was injured.
"We think Mauger has the psyche of a second five-eighths and prefers it there."
McAlister's North Harbour coach Allan Pollock and Aussie McLean, MacDonald's boss at Canterbury, have agreed to showcase each player at number 10.
McLean, who faces a Ranfurly Shield defence against Bay of Plenty this week, told the Dominion Post: "He (MacDonald) will start there and we respect that.
"I'm not going to tell you any other selections because I've broken our team protocol already but it's just that I don't want to play silly games."
Mauger, also of Canterbury, is being rested.
McLean, who is Carter's provincial coach, said he felt for his star player, adding: "I'm more worried about him as an individual - it's irrelevant to me as a coach.
"My hope for him is that as a person he is alright and that it doesn't affect his career. It didn't look to be nice."
Other players in NPC action who may be Henry's 'someone else' include Auckland's Tasesa Lavea, Waikato's Stephen Donald, Otago's Nick Evans or Junior All Blacks player Jimmy Gopperth of Wellington.
Whoever is selected will be in pole position for a place on the Grand Slam tour later this year.