"It started with the Blues and they've continued with it. It sounds like it's a bit niggly, they're not 100 per cent sure what it is. They feel the tendon needs to be cut to relieve the stress and it'll be a six-to-12 week rehab window."
Returning to the Northland mix after a couple of years abroad playing for London Irish, Leicester Tigers and a short stint in Japan, Bowden had resumed full contact training with the Taniwha over the past month.
"He was so close to playing," MacLeod said.
"He was keen as mustard to get in and do some stuff, especially at ITM Cup level so it's a bit of a shame for him. We probably could've taken him to Manawatu but once they found what the issue was they decided it was only going to get worse and they needed to operate straightaway."
Still looking to play a part in Northland's hunt for a win, MacLeod said Bowden had plenty to offer.
"We use him around review and preview, he's a very knowledgeable man ... he'll still add value, he's keen to be involved."