The former Chelsea and England assistant manager was a surprise appointment when Carrick took charge last month.
Asked about how the deal came about, Carrick explained how his brother, Graham, knew Holland from their time together with England at St George's Park.
"When talks were progressing and it looked like I might be coming in, I had conversations with my brother and we ended up mentioning Steve," said Carrick.
"He knew him from the FA and I have come across Steve a number of times.
"I was fully aware of his experience and quality and we clicked straight away.
"He grew up being a massive United fan, which helped to start with but it was also being successful at Chelsea, knowing what it takes to win trophies with different styles, different managers and different types of players."