WINNIPEG - Bo Levi Mitchell hasn't resorted to tucking a four-leaf clover in his shoe or clipping a lucky rabbit's foot to his uniform.

Heading into Friday's game against the Blue Bombers, the Calgary Stampeders quarterback is one of only three pivots who has avoided injury and started every game for his team this season.

Despite his counterparts falling like dominoes across the CFL, Mitchell said Thursday he's not about to change his style.

"I just go out there and play the way I play football," he said, noting he missed three games last year because of injury.

"I'm not going to change anything up. I'm not going to tell myself not to run more or anything like that."

Ottawa's Henry Burris has also stayed healthy this season, while backup Trevor Harris has had the reins from the get-go in Toronto with No. 1 Ricky Ray recovering from off-season shoulder surgery. Ray is back practising.

The number of injured quarterbacks has climbed every year since 2011, according to CFL statistician Steve Daniel.

Going into this weekend's action, the nine clubs have started 19 different quarterbacks because of injuries or performance, Daniel said, adding Bomber Matt Nichols is counted twice as he's started for Edmonton and Winnipeg.

That number will climb to 20 after B.C. plays this weekend, with Jonathon Jennings expected to start for the Lions in place of recently injured John Beck. It moves to 21 when Hamilton finishes its bye week and has to use a new starter for Zach Collaros, who's out for the season with a knee injury.

Daniel said in a phone interview he dug up stats going back to 2000 and a high of 22 different quarterbacks were used in 2007.

He also calculated the number of quarterbacks who specifically missed playing time because of injury and it's been rising the past five years.

Five quarterbacks were injured in 2011 (the lowest in the past 15 years), six in 2012, eight in 2013, 11 last year and it's up to 12 this season, including Ray.

"Since I've been up here, it's always been you need two quarterbacks to win a championship," said Nichols, a six-year veteran acquired Sept. 2 in a trade with Edmonton.

"It's a long season, take a lot of hits. I think I took we counted 18 hits last week. As a quarterback, you take your punishment. Things are going to happen, you just need to be able to have someone there that can be the next man up."

Nichols is a league-high fourth starting QB for Winnipeg this season after No. 1 Drew Willy went down with a knee injury on Aug. 9.

"As an offensive lineman, it's always frustrating to see those guys go down, even if they're not on your team," Bombers 10-year centre Dominic Picard said. "We take pride in protecting the quarterback so it's tough to see, especially our guys."

Stampeders head coach and general John Hufnagel is thankful he's still fielding his No. 1 pivot, but sympathized with the plight of his coaching peers.

"Some teams are down to their third and fourth quarterbacks, and no matter how much you plan you're not going to have that much depth at the position," Hufnagel said.

"It's very, very unfortunate. We need our star players on the field."

The defending Grey Cup champions are 24-5 when Mitchell starts and have kept him healthy despite starting eight different offensive linemen this season.

Calgary goes into Friday's game as heavy favourites, having defeated the Bombers twice this season and 12 of the past 13 meetings.

Winnipeg is also playing in a short week and had only one full practice since last Sunday's 35-14 loss in Montreal. Its record in games with only four days between is 1-1 this season and 1-8 since 2012.

Notes — Calgary receiver Joe West returns after missing four games with a turf-toe injury … Winnipeg receiver Nick Moore is back after missing one game … Linebacker Ian Wild rejoined the Bombers this week and should play at least on special teams.