McKay signed as an amateur free agent with the Minnesota Twins on June 20, 1971, and worked his way through the Twins minor league organization. McKay made his Major League debut on August 22, 1975, hitting a home run in his first at-bat against Vern Ruhle of the Detroit Tigers in an 8-4 victory. McKay appeared in 35 games with the Twins, hitting.256 with two home runs and 16 runs batted in. He spent the majority of the 1976 season in the minor leagues, but McKay did appear in 45 games with Minnesota, batting.203 with no homers and eight RBI. On November 5, the Twins left McKay unprotected at the 1976 MLB expansion draft, and he was selected by the Toronto Blue Jays.
Toronto Blue Jays (1977–79)
McKay was the Blue Jays starting third baseman for their first game on April 7, as the Canadian-born player had two hits in Toronto's 9-5 victory over the Chicago White Sox. In 95 games with the Blue Jays, McKay hit.197 with three home runs and 22 RBI, splitting time between second base, third base and shortstop. McKay became the Blue Jays starting second baseman in 1978, as he played in a career high 145 games, batting.238 with seven homers and 45 RBI. He finished sixth in the American League with six triples, and fifth with a.984 fielding percentage at second base. He struggled in 1979, losing his starting job and spending time with the Blue Jays' Triple-A affiliate, the Syracuse Chiefs, for a majority of the season. With Toronto, McKay hit.218 with 0 HR and 12 RBI in 47 games. On November 5, the Blue Jays released McKay.
Oakland Athletics (1980–82)
McKay signed with the Oakland Athletics on April 4, 1980, and in 129 games with the Athletics, McKay hit.244 with one homer and 29 RBI as a utility infielder. He improved offensively in 1981, as McKay hit.263 with four home runs and 21 RBI in 79 games, helping Oakland reach the playoffs. In the 1981 American League Divisional Series, McKay hit.273 with a home run and an RBI as the Athletics defeated the Kansas City Royals to advance to the American League Championship Series. In the ALCS, McKay again hit.273, with an RBI, as Oakland lost to the New York Yankees. McKay struggled during the 1982 season, hitting only.198 with four HR and 17 RBI in 78 games. He spent the 1983 season with Oakland's A and AAA teams before retiring as a player; he joined the Oakland coaching staff under managerJackie Moore the following season. McKay appeared in 645 games during his career, as he recorded 441 hits and had a.229 batting average with 21 HR and 170 RBI. In six career playoff games, McKay hit.273 with 1 HR and 2 RBI.
Coaching career
The 2017 season will mark McKay's 34th consecutive campaign as a Major League coach, and his fourth with the Diamondbacks. The previous three decades were spent with three teams: the Athletics, St. Louis Cardinals and Chicago Cubs. Although almost every year of his coaching career has been spent as a first-base coach, he spent 1988 as the strength and conditioning coach of the A's. He and José Canseco co-authored a book on proper weight training techniques for baseball players. McKay began a long-term professional association with both manager Tony La Russa and pitching coach Dave Duncan from the midpoint of the 1986, when LaRussa and Duncan took over their respective positions with Oakland, through 2011 with the Cardinals. The three were on staff for six pennant-winning and three world championship teams—the 1989 Athletics and the 2006 and 2011 Cardinals. A close friend of LaRussa's, McKay had intended to retire from baseball when LaRussa did. When LaRussa announced his retirement in 2011, McKay realized he was not ready. He was offered the opportunity to remain with the Cardinals in another capacity, and did not blame the organization for not welcoming him back to his former job as first base coach, as the Cardinals' front office was under the impression that he planned on retiring with LaRussa. He joined the Cubs for the 2012 season. After two years with the Cubs, working under Dale Sveum, McKay was named to the Diamondbacks' 2014 coaching staff by manager Kirk Gibson, replacing Steve Sax. McKay is responsible for coaching the team's outfielders as well as for his work at first base. Duncan, who had been officially out of baseball for two years, returned in an advisory role with the Diamondbacks starting in 2014. Reversing his earlier decision to retire, LaRussa also joined the Diamondbacks in May 2014, in a front office role as Chief Baseball Officer. 2014 therefore marks the 27th season that McKay has worked with Duncan and LaRussa.
