A stress fracture in his lower back from his younger days has not healed. There is pressure on a nerve.
So after trying rest and rehab and that new cute term, monitored bowling loads, Bennett's sights are on the start of next summer.
And yesterday came news that an old favourite, Wellington's quirky Iain O'Brien, has ended his plans for what would have been a dramatic return to the provincial game.
Retirement, the commentary box and perhaps coaching stints now beckon for the 35-year-old.
O'Brien quit the national side after the series against Pakistan in 2009 when he was at the peak of his powers. He got 73 test wickets at 33.27; 322 at 26.06 from 91 first-class games.
He had the trust of then captain Dan Vettori to bowl in clutch situations and was a key cog in the seam bowling mix.
Then he walked away, off to England and a hoped-for professional deal with Middlesex.
That was scuppered by the England and Wales Cricket Board's refusal to class him as a local player. So after regaining fitness it was back to Wellington last year.
He got a provincial contract, but got no further than the nets, a stress fracture in the lower part of a back diagnosed as being more like that of a 60-year-old making up O'Brien's mind for him. Should he have been given a contract in the first place? That's history. But the announcement finally ends an interesting career.
O'Brien was a good example of a cricketer who made the very most of his talents.
He won't be missed as such, as he's been gone for a couple of years.
Meanwhile, the fast-bowling situation within the national side is developing encouragingly, and at pace. Bennett will hope to have his name in the mix in a year or so. Michael Bates gets his chance against Zimbabwe. Then there's Neil Wagner, Pretoria-born but eligible for the tour of the West Indies in June.
You think of Matt Henry at Canterbury, Adam Milne at Central Districts; perhaps Mitchell McClenaghan, fit again and firing for Auckland in the last week.
Interesting days, indeed.