

As a freshman at UCLA, he was named a Singles All-American and the Pac-12 Freshman of the Year. 1 player coming into college according to the ITA. However, he lost in the first round of the main draw to fellow qualifier David Goffin. While still a junior, he won the men's singles title at the amateur Ojai Tennis Tournament in 2013, and also qualified for the 2013 Cincinnati Masters at age 18 by defeating top 100 players Nicolas Mahut and Steve Johnson. In 2012, he reached a career high ranking in the ITF World Tour Junior Rankings of number 12 and won the 18s singles title at the 2012 Easter Bowl.

McDonald was a semifinalist in the boys' singles of the 2012 Australian Open. He won the 2016 NCAA Division I Tennis Championships in both singles and doubles. He reached a career-high singles ranking of world No. Michael Mackenzie Lowe "Mackie" McDonald (born April 16, 1995) is an American professional tennis player.

86–99 (46.5% in ATP World Tour and Grand Slam main draw matches, and in Davis Cup)ģ4–48 (41.5% in ATP World Tour and Grand Slam main draw matches, and in Davis Cup)
