OTTAWA — Stopping Calgary's two-pronged running attack may be key to pulling off an upset win for the Toronto Argonauts in the Grey Cup game.

The Stampeders can give the ball to a bulldozer like Jerome Messam to take up the middle or, as they used to great effect in the CFL West Division final, pitch it to speedy Roy Finch on the outside.

If Toronto can slow down the Calgary ground game, it greatly improves their chances of limiting veteran quarterback Bo Levi Mitchell and his array of top receiving targets.

"It's extremely difficult to game plan against two completely different but still dynamic running backs," Argonauts defensive end Victor Butler said Thursday. "The guys are explosive, they make all the reads.

"Messam's got such great patience in the hole. The Calgary team has so many weapons, so many ways of hurting you, it's hard to focus on just one. Our job is to execute and stay sound in our approach. If we can be physically, mentally and emotionally strong I think we can come away at the end of the day with a W."

Finch, the league leader in kickoff and punt returns and the West Division nominee for special teams player of the year, is not always used in the Calgary ground attack. He had only 21 carries this season for 114 yards, although he missed two games early in the season due to a suspension for a positive test for an amphetamine, which he said was part of his medication to treat attention deficit disorder.

Against Edmonton last week, Finch turned on the burners for a 50-yard touchdown run in the second quarter that put the Stamps ahead to stay in an eventual 32-28 victory.

He had four carries for 81 yards, while the six-foot-three 255-pound Messam picked up 71 on 13 rushes.

"It's definitely a change of pace, to say the least," Argos linebacker Bear Woods said of the two Calgary backs. "You see a lot of teams doing that.

"We played (Saskatchewan's) Marcus Thigpen last week. He's a speed guy just like Finch. You just have to be ready and know during the game what to expect. It'll take continuity football, whether it takes three guys to bring down Messam or three guys to corral Finch."

Coming up with a game plan to stop Calgary falls to defensive co-ordinator Corey Chamblin, who was lured back after a season and half out of football when Marc Trestman took over as coach in late February.

He's aware of what Calgary can do on the ground and in the air. They are a team of veterans who are in their fourth Grey Cup game in six years, although they are coming off an upset loss to Ottawa in last year's championship game.

Chamblin said the Argonauts have a "carbon copy" of Finch and Messam to practise against on their own team in running back James Wilder Jr. and kick returner Martese Jackson, but that won't make it easier in the game.

"We know they have power and speed," said Chamblin. "You have to be gap-sound and you have to be fundamentally sound in terms of your tackling.

"On Messam, you have to bring more than one to the ball. You've got to gang tackle him because he's a linebacker in a running back's number."

He hopes the offence will help out by keeping the Calgary attack off the field.

He called his own quarterback Ricky Ray "the best defensive player on the field for us.

"Because of how explosive their offence is, the best defence we have now is our offence. It's making sure that we don't have to face them as much."

Ray knows the old saying that the best defence is a good offence and says his team can take that approach.

"We've been doing a better job of that," said Ray. "We've improved a lot in our running game throughout the year and it's really become a weapon for us.

"That's where you can really chew up some clock. And then we've just got to execute better in the passing game."