Macari was a regular during the four years Sexton was in charge of the club between 1977 and 1981 and described the London-born manager as "football mad" and "a real gentleman".
"Of all the managers I worked with, Dave Sexton was my favourite," Macari told ManUtd.com.
"At United I also had Tommy Docherty and Ron Atkinson, who were both larger-than-life characters, sharp and witty. But sandwiched between them was Dave Sexton, who was the polar opposite.
“Dave was laidback, chilled out and a very nice man. He was football mad - he lived for the game - and a real gentleman.
"After I left Old Trafford I saw Dave quite a few times at various football matches and he always had a smile on his face. His name for me was "Little Fella"... for obvious reasons!"
Although Sexton led United to the 1979 FA Cup final and oversaw a second-place finish in the league in 1979/80, he failed to win a trophy at Old Trafford and was sacked at the end of the 1980/81 season.
“He wasn't the most popular manager we've had and a lot of fans complained he wasn't tough enough," Macari said.
"I think that's just because he was quietly spoken. He wasn't one to rant and rave or make a scene for the cameras.
"He came from a boxing family - his dad Archie was a pro - and certainly to those of us inside the dressing room he gave the impression that if you stepped out of line he'd knock your head off. He was