All Blacks superstar Barrett on concussion battle: 'The closest I've been to retirement'

All Blacks superstar Beauden Barrett has revealed that he was close to retiring after struggling with concussion in the off-season.

The 100-Test veteran will get his first start of the season for the Blues when they host the Highlanders in a Super Rugby Pacific clash at North Harbour Stadium on Friday.

After coming off the bench in last week's 24-22 win over the Chiefs in Auckland, Barrett gets to start at flyhalf this week.

He's fit again after overcoming concussion symptoms that plagued him during December and January.

In an interview with the New Zealand Herald, Barrett admitted he feared the symptoms may force him into retirement.

"It was extremely challenging. The hardest thing about this one was not finding the cure. That's the million-dollar question with a lot of these concussions. It was frustrating," he said.

"Typically the December-January months are the festive fun times where you decompress and spend time with friends and family. I did that, but it was annoying with a headache all the time.

"I'm well aware of how concussion can lead to retirement if it doesn't work out. Kane, my brother, had to give up his career because of it. I see plenty of good friends and team-mates have done the same in the past."

Barrett said he tried to stay positive.

"It's probably the closest I've been to retirement and I certainly wasn't ready for it. I'm only 30, and I've still got plenty to give. Being back fit and healthy, I'm grateful to be here now and hopefully contribute well to the Blues this season."

After playing against the Chiefs last weekend, Barrett admitted that he was nervous and that "there was a lot of doubt".

The Blues are seventh on the 12-team standings with one win from two matches.

Friday's clash at North Harbour