Macdonald (33) last played for the Highlanders in 2008, before moving to Wales to join Newport Gwent Dragons.
He then landed in Melbourne, playing for the Rebels in their inaugural season, before heading home to Invercargill, where he intended to put his feet up and possibly play out a season for Southland.
But Highlanders coach Jamie Joseph knew of the big lock's movements, and swiftly called him into the wider training squad.
With injuries to Jarrad Hoeata and Josh Bekhuis, Macdonald has been called upon in action and now finds himself back in Highlanders colours.
"To be honest, I never thought I would come back. But the fire is still there and I'm trying to contribute as much as I can," he said.
"It is very, very different from when I left. The first week back was pretty tough on the old body. There are a few familiar faces and some new guys. But that is rugby, really. It is a carousel, where guys jump on and off."
Macdonald played 32 games for the Highlanders until the end of the 2008 season, and said he enjoyed his time overseas.
"In Wales, the rugby could be quite different throughout the year, When we started and at the end, when the weather was a bit better, it was more expansive. But in the middle of winter we kept it pretty much in the pack.
"Right through the time there we were always thinking of coming home. But when the time came we actually thought maybe we were going to miss this place. It had been a lot of fun, and we made some good friends."
His year with the Rebels was not a great success on the field, as the Melbourne team finished last on the table, but Macdonald said he still enjoyed himself.
"We made an impact in Melbourne and were actually drawing bigger crowds than the Storm. The effort was there but none of us had lived in Melbourne before and never played together. We were trying to jump in a boat together and sail straight away."
Macdonald and partner Michelle have two children, Iwi (18 months) and Kade (4 months).
His family has stayed in Invercargill but will move to Dunedin if Macdonald is upgraded to the full Highlanders squad. That decision is likely in a couple of weeks.
Until then, Macdonald will be working hard, starting with today's pre-season game against the Chiefs in Queenstown.
The Highlanders will want to improve markedly from last week's disappointing loss to the Crusaders in Greymouth.
The Chiefs should have plenty of vigour in their play, coming off a comfortable 36-0 win over the Rebels last week.
Highlanders v Chiefs
Queenstown, today, 5pm
Highlanders: Kurt Baker, Telusa Veainu, Ben Smith, Glenn Dickson, Hosea Gear, Lima Sopoaga, Aaron Smith, Nasi Manu, Doug Tietjens, Adam Thomson, Culum Retallick, Nick Crosswell (captain), Ma'afu Fia, Jason Rutledge, Bronson Murray.
Reserves: Andrew Hore, Chris King, Hoani Macdonald, Elliot Dixon, Jimmy Cowan, Chris Noakes, Buxton Popoali'i, Nemia Kenatale, Brayden Mitchell, Josh Bekhuis.
Chiefs: (from) Phil Burleigh, Aaron Cruden, Andrew Horrell, Richard Kahui, Tawera Kerr-Barlow, Brendon Leonard, Tim Nanai-Williams, Lelia Masaga, Maritino Nemani, Robbie Robinson, Asaeli Tikoirotuma, Jackson Willison, Ben Afeaki, Sam Cane, Craig Clarke (captain), Shane Cleaver, Marcel Cumming-Tonne, Mike Fitzgerald, Rory Grice, Tanerau Latimer, Fritz Lee, Ronald Raaymakers, Brodie Retallick, Mahonri Schwalger, Tony Smith, Ben Tameifuna, Sona Taumalolo, Kane Thompson, Scott Waldrom.