The 26-year-old skippered the British women's match racing team at the London 2012 Olympics last summer, sailing on the Weymouth shores as the world champion from 2010.
However, having also won silver at the worlds in 2011, things didn't quite go to plan as the crew of Macgregor, her younger sister Kate and Annie Lush finished seventh at the Games.
It was the trio's one and only chance to claim Olympic success in women's match racing with the Elliott 6m removed from the Olympic programme for the Rio 2016 Games.
All three have gone their separate ways since with Macgregor senior finding herself in a new class for the Olympics in 2016, the Nacra 17 which is a mixed gender multihull.
She started sailing with Phipps in October and hasn't looked back since with the pair to make their competitive debut together on the water at the upcoming Princess Sofia Trophy.
And, while playing down their expectations from the regatta in Palma, Macgregor revealed it didn't take long for her to realise Phipps was the man for the new Olympic campaign.
"The Nacra 17 which is a massive change for me, it is a completely new style of sailing and I have a huge amount to learn," said MacGregor.
"But I am really enjoying it, it is a big mountain to climb but it is a great new challenge and it gets me out of bed in the morning.
"Either way I was really hungry to do another Olympic cycle and had match racing continued I would have carried on with that.
"I started sailing with Tom in October and, we are not expecting a top finish in Palma, we are just looking forward to sailing with each other.
"Tom and I complement each other very well, he has a huge amount of catamaran experience and I have a huge amount of campaigning experience.
"We went out to test together and after three hours we thought 'let’s do it'."