Already minus star receivers Kamar Jorden (knee), DaVaris Daniels (collarbone) and Eric Rogers (knee), Calgary suffered another blow at that position before halftime Friday.
After a high hit late in the first quarter, Reggie Begelton walked off holding his right arm and did not return.
The Stampeders moved to 11-2 atop the CFL's West Division. Calgary became the first team to secure a playoff berth this season.
Calgary is now intent on clinching first for a direct trip to the division final at home.
"If you're in the dance, you've got a chance to win it,'' Calgary head coach Dave Dickenson said. "I obviously want a home playoff game and a bye, but it's going to be a big challenge.
"We're decimated right now at receiver. Right now, I'm in one of those moods just trying to figure out who is going to be on the field next week. Good to get the win, but definitely lost some more guys.
"Might have to see if any of the running backs can play receiver.''
Dropping to 3-10 in the East Division shrunk Toronto's playoff chances and further opened the door to a team out of the West crossing over for a post-season berth.
The Argonauts lost their fifth in a row and fell to 0-6 on the road this season.
"We're trying to stop the bleeding so to speak and we haven't been able to do that collectively for a number of different reasons,'' Toronto coach Marc Trestman said.
The Argos gave up 120 yards in penalties to Calgary's 11.
Throwing to a receiving corps that included three national players and another player activated from the practice roster, Calgary quarterback Bo Levi Mitchell still amassed 307 passing yards and threw a pair of touchdown catches.
"Bo never skips a beat,'' Stampeder receiver Marken Michel said.
Michel scored a pair of touchdowns, Juwan Brescasin caught a touchdown pass and backup quarterback Nick Arbuckle scored on a one-yard plunge.
Calgary had another receiver scare with Brescasin as his halftime treatment kept him out of the game until midway through the third quarter. But he returned for a touchdown catch late in the game.
Rene Paredes kicked three field goals for the Stampeders in front of an announced 24,126 at McMahon Stadium.
Toronto quarterback McLeod Bethel-Thompson and backup James Franklin scored short-yardage touchdowns for the Argos, while kicker Zack Medeiros made one of two field-goal attempts missing one from 47 yards.
Mitchell improved to 10-0 in career starts against the Argonauts. The Texan completed 20 of 34 pass attempts.
"The depth is being tested and guys have responded,'' Mitchell said. "That's the beauty part about it.''
Bethel-Thompson dropped to 2-5 as a starter since the Argos lost Ricky Ray to a season-ending neck injury in Week 2.
Bethel-Thompson was 31-for-45 in passing for 273 yards. He scored a one-yard rushing touchdown with two seconds remaining in the game.
Argos safety Jonathan Dowling picked off Mitchell early in the fourth quarter, but Stampeder defensive lineman Derek Dennis stripped him of the ball for teammate Markeith Ambles to recover.
Calgary capitalized on the turnover with Brescasin scoring on Mitchell's three-yard toss.
Calgary struggled to punch the football in from the red zone for three quarters. The Stampeder offence relied on chip shots from Paredes to wrest points out of three drives.
But Michel's second touchdown of the night on a 21-yard catch-and-run gave the Stampeders a 21-point cushion to start the fourth quarter.
A Brandon Smith interception midway through the third gave Calgary the ball on Toronto's 11-yard line. Arbuckle scored on a one-yard plunge.
"The game was tight until we got that pick,'' Mitchell said. "After that we kind of ran away with it.''
Former NFL Pro Bowler Dexter McCluster made his CFL debut with the Argos, rushing 27 yards on four carries.
Instead of returning to Toronto, the Argonauts remain in Calgary next week to prepare for next Saturday's road game against the B.C. Lions.
Calgary's next game is in Montreal against the Alouettes on Thanksgiving Day.