Richie McCaw is baby Charlotte's favourite as Gemma makes Black Sticks hockey return

Richie McCaw is baby Charlotte's favourite parent, according to mum Gemma.

The former international hockey star, who has recently come out of retirement, posted an adorable Instagram picture of the former All Blacks captain with baby Charlotte at a swimming lesson.

Charlotte turns one this month.

"Is there anything cuter than a Dad swimming with his baby?," Gemma McCaw wrote.

"These two have spent some quality time together this week while I've been training and secretly I think he's the favourite #daddysgirl."

Gemma McCaw was recently named in the Black Sticks' squad as the team builds towards the 2020 Olympics, returning to the fold after having played 246 matches before retiring in October 2017.

As a result of her increasing workload, she told Now To Love that Richie and her mum Michelle would both be stepping up to help out as she ramps up her training in an effort to make the Games.

Her mum would take a year off from teaching to help with Charlotte, while Richie, who now works as a helicopter pilot, will also scale down "so they'll share the care of Lottie when I'm training," Gemma told the magazine.

Last month Gemma opened up about the "challenges" of juggling motherhood and her return to the Black Sticks in an interview with Radio Sport's D'Arcy Waldegrave.

"A little tiny part of me felt that there was a little bit of unfinished business.

"I felt like I really missed getting out there with the girls and playing the sport that I always loved. I filled in for a club hockey game when Charlotte was four months old and I kind of crossed the line out onto the field and I had that white line fever again," she said.

"That's where it all started. I was fortunate enough to play NHL and then some time in the Aussie league and that's when I guess I started to get a little bit more serious about it and think 'I would actually love to play again at that high level'.

"A year ago just before having Charlotte I didn't think I'd probably be lining up back in the team. But [I'm] grateful for the opportunity and very excited with the year ahead and what's to come."