The 35-year-old former Notre Dame star returns under centre Sunday when Toronto hosts the Montreal Alouettes in a battle for first place in the CFL East Division. And the veteran backup hopes the third time is indeed the charm.
"Doesn't get any bigger, it's almost like a playoff game or Eastern Final, however you want to look at it, we just know it's a very big game," Jackson said after the team's walkthrough Saturday.
With No. 1 quarterback Ricky Ray still sidelined with a knee injury, Jackson makes his third straight start. He played with poise in a 23-10 victory over Winnipeg but then was out of sync in last weekend's 36-10 loss to the Saskatchewan Roughriders — a performance he said he would grade "not very high at all."
"There was probably up to eight to 10 plays out of 46 that I could have done something better or tried to either run around and try to help our team make a play or do something," said Jackson, who has completed 48-of-90 passes for 515 yards, two touchdowns and a pair of interceptions over his last two starts.
"As a quarterback, you're always going to take the brunt of it whether you win or lose, but I'm one of those types of guys, I don't point fingers, if I do it's going to be at myself."
Sunday's matchup at Rogers Centre is huge for both teams. The Alouettes (8-6) will clinch the season series and a home playoff date with a victory. Montreal was a 31-10 home winner over Toronto (7-7) in their last meeting three weeks ago but have lost their last two games.
"This is a big game for us, we can do the math, we can figure it all out. And so can Toronto," said Als coach Marc Trestman. "From a season perspective and game perspective, this is clearly a landmark game for us this season. It's a very very important game, no doubt about it."
A win would move Toronto into a first-place tie, but the Argos would get top spot based on winning the season series. And that's important because if the two teams ended the season tied, the winner of the season series would get the higher spot in the standings.
The advantage of finishing first in the division is receiving a first-round playoff bye, then hosting the semifinal winner in the East final, needing just one post-season victory to advance to the Grey Cup on Nov. 25 in Toronto.
The second-place finisher will host the East semifinal, with the winner of that game advancing to the conference final.
However, the Argos are struggling too, having won just one of their last four games.
"Losing your starting quarterback, it hurts," coach Scott Milanovich said, when asked about the Argos' inconsistency. "Your starting quarterback is the guy your team looks to. Jarious has done as good a job as anybody could do as backup and our teams believes in him. But we'll be looking forward to getting Ricky back, that's why we traded for him in the off-season, because we wanted him here.
"But nobody is looking back in the meantime. Jarious has to go out and play well and we have faith in him."
Milanovich hopes Ray will return Friday when Toronto faces the Winnipeg Blue Bombers.
Jackson said he feels far more at ease running the offence than he did three weeks ago when Ray went down in Montreal.
"I was somewhat comfortable with the gameplan at that time," he said. "But at that time I hadn't had any reps since training camp. Now I've had three or four weeks of reps, so now I feel like it's a different game from my standpoint."
The Riders ran roughshod over Jackson and the Argos last weekend however, as Jackson finished 16-of-31 passing for 162 yards with a TD and interception before giving way to rookie Trevor Harris in the fourth quarter.
Jackson said in some ways it's more difficult being a backup quarterback.
"To me I think there's more pressure on the backup than there is on the starter, because you actually know you're going to get in the game and play, if you make mistakes you have time to make amends for it, or next week so to speak," he said. "I just have to be ready at all times and my role right now is actually being the guy so hopefully I can get in there and make things happen."
The Argos could see one key veteran return to the field Sunday. Noel Prefontaine has been cleared to play after missing 13 games. The kicker underwent hip surgery in the summer that he felt could have ended his career.
Montreal, who will be missing S.J. Green — the CFL's leading receiver — are coming off a 27-22 loss to Winnipeg that left quarterback Anthony Calvillo feeling like "we're a last-place team."
The Als turned the ball over five times — three fumbles and two interceptions. Two of the turnovers came in the scoring zone.
Trestman is eager to see how his team responds Sunday.
"I think our team is excited for the opportunity to play in a game like this," Trestman said. "I think we appreciate where are in the standings, but we also respect the team we're playing and we've got to go on the road now and win this game. It's the same for both sides."
Sunday also marks a CFL Pink game to raise awareness for women's cancers.
Calvillo said the game holds special meaning — he and his wife have survived cancer scares.
"I remember last year when we stepped on the field (for the CFL Pink game) in Winnipeg, and I didn't realize how emotional it was going to be to be honest with you," said Calvillo, who will wear a pink quarterback towel and have pink on his shoes. "Once you got on the field you realized that everybody out there has this pink on for a reason, for people who are touched by cancer.
"So this year it will be a bit more different."