TORONTO - The Toronto Argonauts will have to make their playoff push without star quarterback Ricky Ray.

The Argos released their depth chart for Friday's game against the Ottawa Redblacks and Ray is out for the must-win home game against Ottawa after suffering a concussion in Sunday's 17-14 road loss to the Montreal Alouettes. Backup Trevor Harris is expected to make his first CFL start against the Redblacks.

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"Ricky would be doubtful, at best," head coach Scott Milanovich said. "I'm planning right now on Trevor playing but it's not out of the realm of possibility (Ray) could play.

"He'd have to essentially get cleared and then come and say, 'Listen, you've got to play me, I've got to be in there.' There's a lot of stuff that has to take place before that can happen."

Toronto (7-10) remains in playoff contention but doesn't control its destiny. The Argos must beat expansion Ottawa (2-15), then have Montreal (9-8) defeat the Hamilton Tiger-Cats (8-9) on Saturday afternoon to secure second and host either B.C. or Saskatchewan in the East Division semifinal Nov. 16.

Hamilton would clinch second place by beating Montreal and could take first place — and home field for the East final Nov. 23 — if that victory was by eight points or more.

Ray, 35, has made all 17 regular-season starts and leads the CFL in attempts (620), completions (425), passing yards (4,595), TDs (28) and completion percentage (68.5). Toronto leads the league in passing yards (4,767), touchdowns (29) and efficiency rating (95.3).

Ray, in his 12th CFL season, has 15 interceptions — tied with B.C.'s Kevin Glenn for second-most. But Toronto's receiving corps has been plagued by injuries this season to veterans Andre Durie, Jason Barnes, Chad Owens and John Chiles as well as promising rookie slotback Anthony Coombs.

"The possibility of not having (Ray) this week is big ... he's our leader," Owens said. "If Ricky can't go, I'm really excited to watch Trevor Harris play a full football game.

"He's a competitor, a hard worker on and off the field. He comes to work every day and prepares like he's playing. I know if he's going to get his opportunity he'll be ready and we'll be right there to have his back."

Harris, 28, is completing his third CFL campaign, all with Toronto. After spending his first two seasons as the No. 3 quarterback, Harris was promoted to Ray's backup after Zach Collaros signed as a free agent with Hamilton this off-season.

Harris has played sparingly this season, completing 16 of 24 passes for 168 yards. Over his CFL career, the former Edinboro University star is 33 of 58 passing (56.9 per cent) for 424 yards with one TD. He has also rushed five times for 20 yards.

Harris replaced the injured Ray late in Sunday's game, completing one of four passes for eight yards.

"I thought he was poised," Milanovich said. "I liked the look in his eye.

"A coach can understand there's a look in a quarterback's eye when they go into a game, particularly a meaningful game, where you can tell if they're with you or if their nerves are there. I thought Trevor was in a good mindset, which is encouraging for Friday night."

Harris, a six-foot-three 209-pound native of Waldo, Ohio, said his preparation this week won't differ from what it has been since joining the Argos.

"You've got to prepare every week as if you're the starter," he said. "As cliche as that sounds, as a quarterback that's really what you have to do and your job is to be ready at any time.

"But you'd be lying to say there's not a little more sense of urgency, there's not a little more antsiness to get excited that there's a possibility you could play."

Harris enjoyed a productive career at Edinboro (2006-'09), amassing 11,899 passing yards and 100 TD passes. In his final collegiate game, Harris completed 50 of 70 passes for a Division II playoff-record 630 yards and five TDs while running for two more in a wild 84-63 playoff loss to West Liberty.

Harris has spent three years learning from Ray, a three-time Grey Cup champion and one of the most accurate passers in CFL history (67.6 career passing percentage). Last year, he watched Collaros go 5-2 as Toronto's starter replacing an injured Ray.

"Every quarterback is different, every situation is different," Milanovich said. "I just want him to play within himself.

"(Harris) has got to play the game the way he feels comfortable and we need to give him an opportunity and give him things that he's comfortable doing. I want him to play aggressive, smart football."

Harris agrees.

"There's no different mindset, no different approach," he said. "I'm just going to stay within the offence and do what I do.

"Ricky and I are pretty much the same style of player. I'm not ever claiming to be Ricky Ray, he's a Hall of Famer, we just kind of have the same sort of style."

And should Ray not play Sunday, he'll still be on Toronto's sidelines.

"When you have a Hall of Famer right by your side that's done this a few times, I'm probably going to be picking his brain," Harris said. "You learn from Ricky by watching him.

"What you see on the field is his personality in life. He never gets too excited. I swear if you told him you won $5 million he'd be like, 'Oh, cool.' That's just him."

Milanovich said Toronto's psyche remains solid despite Sunday's disappointing loss.

"I think we're fine," he said. "It was disappointing going into the fourth quarter with a touchdown lead and not being able to finish it but there were some positives we can take out of it too.

"That's the hottest team in the league and we had an opportunity to win the game. We didn't and we've got to forget about it and understand our season isn't over, that we have to take care of our business Friday night and see where it goes from there."

Toronto also lost cornerback Vincent Agnew (Achilles) and defensive lineman Marcus Thomas (foot) to season-ending injuries Sunday. On Tuesday, the Argos released receiver/kick-returner LaVon Brazill.