Born in Ontario, MacKenzie attended Yale. He signed with the Braves out of school in 1956. MacKenzie reached the big leagues with the franchise, at the time based in Milwaukee, in 1960. He pitched 15 1/3 innings over parts of two seasons before joining the expansion Mets in 1962.
MacKenzie logged a career-high 80 innings for the inaugural team in Queens, posting a 4.95 ERA. As the AP notes, his 5-4 record made him the only pitcher with an above-.500 mark for a team that ultimately went 40-120. MacKenzie was traded twice the following season, going to the Cardinals and Giants. He also saw some action with the Astros in 1965.
Over parts of six campaigns, the left-hander posted a 4.80 ERA across 208 1/3 innings. He struck out 142 hitters and picked up eight wins. After his playing career, he coached baseball and hockey at his alma mater throughout the 1970s. MLBTR sends our condolences to MacKenzie’s family, friends and former teammates.