Vikings offensive coordinator Darrell Bevell confirmed Jackson's status as the starter for Sunday's game but referred long-term questions to coach Brad Childress, who was not immediately available for comment.
Gus Frerotte is recovering from a fracture in his lower back but returned to practice Wednesday and is healthy enough to be the No. 2 quarterback Sunday, Bevell said.
Minnesota leads the NFC North with a 9-5 record and can clinch the division outright by beating Atlanta.
In about six quarters of play since replacing Frerotte, Jackson has a 141.7 passer rating. Frerotte won eight of 11 starts after taking over for Jackson in September.
"Tarvaris has shown us an outstanding presence in there," Bevell said Thursday. "He's run the offense. He's done exactly what we've asked him to do.
"He's played well. He's brought us to two victories in two games. He's done what he's supposed to do. I still think the other part is where Gus is at. [We need to] make sure we can bring him along and get him as healthy as we can get him to continue to make this push. How it goes for the weeks after that, we'll just play it out from there."
The key to the transformation, Jackson said, was that he has
learned to loosen up.
"I almost killed myself trying to be perfect," Jackson was quoted as saying by The Associated Press.
"Now I'm not putting as much pressure on myself. I'm just having
Bevell was asked a series of questions about the long-term implications of starting Jackson when Frerotte is healthy enough to be the primary backup.
Asked if the decision applies only to Sunday's game, Bevell said: "I wouldn't say that."
Asked if it was a permanent decision, Bevell said: "I wouldn't say that, either. I'm just saying right now. That's what we're doing this week. Beyond this week, I'm not going to speak for [Childress]."
Frerotte said he
"definitely" felt good enough to play against the Falcons on
Sunday, but was notified of the decision on Thursday morning.
"It's up to coach," Frerotte said. "Obviously I'm not happy
about it, but it's coach's decision. I'll be out there to help this
team, no matter what."
NFL blogger Kevin Seifert covers the NFC North for ESPN.com. Information from The Associated Press was used in this report.