THE CANADIAN PRESS

MONTREAL -- In Arkee Whitlock's eyes, the main difference between him and the man he's replacing as Edmonton's starting running back is very obvious.

Already deprived of their prized free agent acquisition Jesse Lumsden in week two of the Canadian Football League season, the Eskimos have placed their faith in a rookie who presents a very different look for defences to start against the Montreal Alouettes on Thursday night (TSN, 7:30 p.m. ET).

"I'm a lot smaller," Whitlock said with a laugh Wednesday when asked to compare himself to Lumsden. "Obviously Jesse's a bigger, more powerful back that also has speed. I think I'm just a little different because I use my speed and vision to avoid a lot of contact. I'm a very instinctive runner."

The oft-injured Lumsden did not survive the first quarter of his first game in green and gold, separating his shoulder on a hit by Winnipeg linebacker Siddeeq Shabazz in a season-opening 19-17 win, an injury that will cost him at least nine weeks.

Eskimos GM Danny Maciocia said he knew Lumsden came with a risk, considering his problems with shoulder, knee and ankle injuries over his five years with the Hamilton Tiger Cats.

This is why Maciocia felt it was important to have a backup plan, and he said Whitlock has been on his radar for the last couple of years. Whitlock had a prolific collegiate career at Southern Illinois University, claiming the school's all-time records for all purpose yards, scoring and rushing touchdowns in only three seasons.

He signed as a rookie free agent with the Minnesota Vikings in 2007 and spent the past two seasons on their practice roster before signing with the Esks in April.

"We knew, just because of Jesse's history, that if something did happen we'd have to be able to punch someone in there and pick up where we left off," Maciocia said. "We didn't think it would be in week two, but (Whitlock) has to take this opportunity and run with it."

Edmonton's chances of winning Thursday will depend greatly on how Whitlock and backup Calvin McCarty are able to perform on the ground. In last year's East Division Final, the Eskimos managed only three rushing yards in a 36-26 loss in Montreal.

"We have our philosophy, and that's to run the football," Eskimos head coach Richie Hall said. "Regardless of whether Jesse's in there or not, we have to be able to run the football effectively if we want to be successful."

The Eskimos aren't the only team in this game that will be missing a big offensive weapon, as Alouettes slotback Jamel Richardson will be unavailable after suffering a shoulder injury in Montreal's season-opening 40-27 victory in Calgary.

Stepping into Richardson's shoes will be S.J. Green, a third-year receiver who recently spurned a contract offer from the Toronto Argonauts to remain on the Als practice roster, a decision that is paying quick dividends with this opportunity.

"I'm not approaching this game any differently as I would any other game," Green said. "I'm going to let the game come to me, I'm not going to try and go get the game."

Green had the majority of reps with the starting offence throughout training camp as Richardson recovered from a bout with pneumonia, which gives quarterback Anthony Calvillo confidence that the transition should be relatively seamless.

At six-foot-two, 216-pounds Green is the same height and only eight pounds lighter than Richardson, but Calvillo says that is where the similarities between the two end.

"Nothing is going to change for us, we're going to approach this game as if Jamel was in there," Calvillo said. "Physically they're very similar, but style wise S.J. likes to come out of his breaks a little earlier. That's why it was good that we had a chance to work with him so much in camp."

The Alouettes are coming off a big victory on the road in Calgary last week where Montreal unveiled a more aggressive defensive scheme featuring a lot of man coverage. The result was limiting Calgary to only 272 yards of total offence, and Als head coach Mark Trestman says the game plan shouldn't change much Thursday against Edmonton.

"As Edmonton will see, we're able to play more man-to-man coverage," Trestman said. "In our first game we certainly were more aggressive against Calgary than we were a year ago, and we want to continue that."

Montreal rush end Anwar Stewart said the focus will be to stop the run and force Eskimos quarterback Ricky Ray to drop back to pass.

"We just have to go out there and shut down the run and force them to throw the ball," Stewart said. "Then hopefully we can get some pressure on them and disrupt them."

Whitlock said he doesn't take that as a personal challenge.

"This is my first time playing Montreal, they can't possibly even know who I am," he said. "So I don't take it personally."

But Whitlock definitely hopes to foil that game plan with a solid performance Thursday, while at the same time solidify his hold on the starting running back position for the Eskimos.

"A lot of guys wait in the shadows for this kind of opportunity, and I'm one of those guys," he said. "I'm trying not to get over-excited. I just want to maintain focus and remember first and foremost that I have to take advantage of this opportunity."