Coach Brad Childress wouldn't rule out Harvin for the battle between division leaders, but wasn't overly confident the explosive rookie would be able to play.
"It's tough, certainly behind the eight-ball," he said.
Harvin, dangerous as a receiver and kick returner, missed practice time before the San Francisco and Green Bay games earlier this season and responded well in both. Besides four catches for 51 yards, he returned a kickoff for a touchdown against the 49ers, and had five catches for 84 yards and a touchdown against the Packers.
The Vikings, who can clinch the NFC North with a win and Green Bay loss at Chicago, have 14 players listed on the injury report, all but one of them starters.
That includes running back Adrian Peterson (foot/ankle), right tackle Phil Loadholt (shoulder) and left guard Steve Hutchinson (shoulder). All were limited in Friday's practice, as was quarterback Brett Favre because of a coach's decision.
Favre, Peterson and Hutchinson are probable for Sunday; Loadholt is questionable.
Childress became irritated with reporters who were asking about the hurt players Friday, referring them to the team's injury report that had yet to be distributed.
"I [expletive] hate to talk about injuries," he said. "You get a report ... OK? That fair?"
Safety Tyrell Johnson missed Friday's practice because of a concussion, his third straight day on the sidelines. He's listed as doubtful, though Childress said, "I'm pretty sure he's out."
If Johnson can't play, rookie Jamarca Sanford would likely get his first start.
Right guard Anthony Herrera, out the last two games with a concussion, had a full practice Friday and is listed as probable.
Having a healthy offensive line will be a key because the Bengals have the league's second-ranked rushing defense and fourth overall defense.
Despite the limited time working together as a group, Loadholt said it shouldn't be a problem.
"We practiced good this week," he said. "We got all the looks we needed. We'll be ready."
Cornerback Antoine Winfield, who has missed six games with a foot injury, was limited in practice and is listed as questionable. But he was encouraged by the fact he had no setbacks this week.
"I think this is the week I finally get back out there and get to get some action," he said . "So we'll see how the [pregame] warmups go on Sunday and hopefully I'm up [activated]."
Information from The Associated Press was used in this report.