The 35-year-old seamer picked up a groin injury in the United Arab Emirates last month. Talk about untimely. One good thing might be that it didn't happen a week later or, say, now.
The prognosis was four to six weeks to recover.
He's back bowling off a full run-up, albeit short of 100 per cent intensity. Mills is optimistic.
"It's tracking really well," he said.
He won't play the first three of the seven ODIs against Sri Lanka and, instead, is planning to play a Ford Trophy game for Auckland next Sunday against Northern Districts at Eden Park, having spent the week with the squad training.
He's then expected to play a part in the last four ODIs against Sri Lanka, and then the two to follow against Pakistan.
The naming of the World Cup squad was especially significant for Mills, whose relationship with the tournament is rocky, at best.
Having made his ODI debut in Sharjah in early 2001, Mills played just one game at the 2003 tournament, against Bangladesh in Kimberley.
He missed 2007 entirely through injury and four years ago had appearances against Zimbabwe and Pakistan before a quad injury cut him down against Canada, when he had taken two for two from 2.4 overs.
He's New Zealand's second-most successful ODI bowler behind Daniel Vettori, with 237 wickets from 167 matches, and an impressive average of 26 apiece. He spent time as the world's No1-ranked ODI bowler in 2009.
Given that World Cup record, this tournament will be special.
"I'm absolutely delighted to be named," he said. "It's likely to be my last World Cup and it's been on my radar for some time personally to be in the group and to contribute."
Who gets a starting spot out of the five fast-medium options is among the intriguing elements which will unfold as the tournament progresses.
Tim Southee, Trent Boult, Mitchell McClenaghan, Adam Milne and Mills all have different qualities and they're all desperate to play - perhaps none more so than the oldest in the group.
