So, I decided to take a look. I started in 1979, and these were the Canadian born players who were in the MLB:#OTD 47 years ago, the Houston Astros sign Canadian RHP Gordie Pladson (New Westminster, B.C.) as an amateur free agent.— Kevin Glew (@coopincanada) June 30, 2020
He pitched 20 games in parts of four seasons with the Astros from 1979 to 1982. pic.twitter.com/nqzeIuf4CF
Fergie Jenkins - Hall of famer who retired in 1983, after a long career mainly with the Cubs and Rangers (and a pit stop in Boston)
Reggie Cleveland - retired in 1981 - also one of the best Canadians to ever play for the Red Sox
Bill Atkinson - pitched his last 10 games for the Expos in 1979
Dave McKay - was with the Blue Jays, and played until retiting in Oakland in1982
Terry Puhl - 1978 all star, who played with the Astros until 1990, before retiring in KC in 1991
John Hiller - two time all star who played in Detroit his whole career, before retiring in 1980
Along with the aforementioned Gordie Pladson, that's a total of seven. That's the most there would be until the 1990s.
In 1980, Paul Hodgson had a handful of at-bats for the Blue Jays, and with Atkinson having retired, that kept the total at seven.