First will be Al Oliver. Oliver played for the Expos in 1982 and 1983. Both years leading the league in doubles. 1982 he also led in average and hits while 1983 he also led in grounded into double plays. Oliver was a fairly consistent player for most of his career, He was a multiple time All Star, including his two years with Montreal. He would end his career in Toronto, coming to the Jays from the Dodgers for Len Matuszek. He played 61 games for the Blue Jays, primarily at First and Designated Hitter. He retired at the end of the season, forced to according to the man himself. He ended off with 2743 hits. If not for the collusion of owners, he may have had a shot at 3000.
Next is Alex Gonzalez. He started his career with the Blue Jays in 1994. A rather ordinary player over the course of his time with the Jays, he ended up being traded to the Cubs for Felix Heredia in 2001. In 2004, he spent part of the year with three teams: The Cubs, The Padres, and The Expos. He was traded to the Expos in a Trade Deadline deal involving four teams. He was then sent to the Padres in September in a conditional deal that didn't seem to have a finishing point.
Next is Brad Fullmer.
He started his career as an Expo, drafted in the second round in 1993. He was often injured throughout his career, lasting from 1997-2004. He played for Montreal from 1997-1999, then was part of a three team trade that sent him to Toronto, Lee Stevens to Montreal from Texas, and David Segui to Texas from Toronto.
Damaso Garcia. A rather interesting player for the short time he played. He came to the Jays from the Yankees, in a trade that brought Chris Chambliss and Paul Mirabella to the Jays. He was the regular second baseman from 1980-1986. He was a solid player, but nothing spectacular, making the All Star team twice and not much else. He didn't walk or strike out.
The interest comes from an incident in 1986. He was in a slump and after one game, burned his jersey in order to try to break the slump. The manager at the time, Jimy Williams, was not happy and confronted Garcia in front of the team. He ended up getting traded to the Braves at the end of the season.
Now a part time player, he was on the Expos in 1989. Again, he was a solid piece, but not enough to keep a job. After he retired he was diagnosed with a malignant brain tumour that limited his mobility.
Darrin Fletcher was a bit player for the Dodgers and the Phillies before going to Montreal in a trade. Getting regular playing time, he turned out to be a solid player. He signed with the Jays in 1998 and had his best season in 2000. In 2002, he retired midseason.
In 2000, Dave Martinez tied a record for playing on four teams in the same season. Traded on May 12 from Tampa to the Cubs for Mark Guthrie. Then June 9 he was traded to the Rangers for Brant Brown. Finally August 4 he was traded to the Jays for Pete Munro.
Speaking of Mitch Webster, here he is! He came to the Jays in the 1979 minor league draft from the Dodgers. He spent 1983 and 1984 bouncing between Toronto and Syracuse. In 1985 he was traded to the Expos for Cliff Young. He was a regular for the Expos in 1986 and 1987, leading the league in triples in 1986. In 1988 he was traded to the Cubs for Dave Martinez and went on to be a fourth outfielder for many years, retiring in 1995.
David Segui spent 337 games for Montreal from 1995-1997 and 31 games for the Jays in 1999. He did sign as a free agent in 2000 but was traded to the Rangers in the deal that brought Brad Fullmer to the Jays.
Fred Manrique played a grand total of 33 games between the Jays and Expos. He was a rather forgettable player overall, with his fame in being part of a trade involving Sammy Sosa.
Jim Mason was an original member of the Blue Jays, drafted from the Yankees in the Expansion Draft. He played with the Jays until May 9 when he was traded to the Rangers with Steve Hargan for Roy Howell.
In 1979, he played for Montreal and was rather unremarkable.
He retired after the 1979 season.
Matt Stairs was signed as an undrafted free agent by the Montreal Expos. (At the time, Canada wasn't part of the Amateur Draft) He ended up only playing 19 games for the Expos in 1992-1993 before bouncing around the majors. In 2006, he signed with the Jays as a free agent.
He played regularly with the Jays and then was traded to the Phillies in 2008. He ended his career with the former Montreal Expos when he played for the Washington Nationals.
Kenny Williams is better known as the Executive Vie President for the Chicago White Sox, but before that he was a bit player for six seasons. He was picked up by the Jays from the Tigers in 1990, when the Tigers put him on waivers. Williams was the starting centre fielder when Dave Stieb threw his no-hitter. He also had a bizarre baserunning incident in 1990. He was running from second, ran over the third base coach, had to run back to second and was able to get back. He ended up scoring a run.
In 1991 he was waived by the Jays and picked up by the Expos. He played 34 games and was released by the Expos at the end of the season. He then went into scouting for the White Sox and the rest is history.
In 1999, he signed with the Expos. He played 93 games for them before going to Japan for a year.
He signed with the Jays in 1995, playing in 1996 and part of 1997, when he was traded to the Dodgers in August.
Overall, he has the most stolen bases by a player who never played in an All Star game.
Randy Knorr was a backup catcher for the Jays between 1991 and 1995.
He didn't hit much and generally played when Pat Borders took a day off.
He signed with the Expos for the 2001 season where again, he was a backup. He stayed with the Expos in a minor league role until 2004, when he played for the Edmonton Trappers and became a Canadian citizen.
He since coached for the Nationals until 2015.
Rene Gonzales was drafted by the Expos in 1982, in the 5th round. He played for the Expos in 1984 and 1986, playing 40 games total. He was part of the trade that brought Dennis Martinez to the Expos from the Orioles. In 1991, he was traded to the Jays for a minor league player.
Through his career he was a role player, filling in where he was needed off the bench.
He generally didn't hit very well as a Jay. 1979 was the year with the most playing time, hitting
In 1992, he signed with the Expos to back up Gary Carter. He played 33 games before being released due to the emergence of Darrin Fletcher.
Jays: 1987-1992, 2000
I actually did not realize he played for the Expos at all. He signed with the Expos after the Phillies released him.
He has the distinction of being on both teams' rosters in their first season. In both cases, he was traded to the team: to the Expos from the Dodgers, and then to the Blue Jays from the Athletics. He was also the only All Star for the Jays in 1977.
In both cases, a free agent signing. 1988 was his last season as a player.
A rather forgettable player on forgettable teams.
Expos and Jays: 1985
He got both teams in during his last major league season. Released by the Expos and signed by the Jays.
He not only played for both the Jays and Expos but has also broadcast games for both teams. He currently does Miami Marlins games.
He was traded by the Reds for Pete Rose in 1984.
He retired after the 1990 season because he generally could not hit. He moved into coaching and managing.
Jays and Expos: 1979
It's odd. I believe the picture used on the card to the right has him in an Expos away uniform with the Jays hat airbushed on. It has the inconsistent sizing that plagued Topps since 1977.
He was a home run hitter in the minors but never got past part time status in the Majors. In 1980 he went to Japan. Sadly, the first Samoan-born player was murdered in 1990 in Samoa.
Other players that have toiled for both teams in the Great White North that I don't have cards for are: Michael Barrett, Tony Batista, Raul Chavez, Maicer Izturis, Tony Johnson, Luis Lopez, Ken Macha, Juan Rivera, Hector Torres, and Brad Wilkerson.