Duensing is 1-2 with a 3.12 ERA in 30 appearances this season and has started 50 games since 2009, including 28 last year.
As a team, the Twins hold the second-worst ERA in the Majors at 5.05, trailing only the Rockies at 5.33.
"I'm not looking to take people out of the rotation," said Twins manager Ron Gardenhire. "If you start, and you do well, we'll find something. Duensing's been a starter and has all the confidence in the world, it's just going to be about how this is going to help him getting back to throwing."
While the Twins continue to feel out the situation, Gardenhire said the staff hopes to limit Duensing's pitch count to no more than 60.
"How he'll do, you never know because he hasn't been in this situation," Gardenhire said. "I feel pretty good about running him out there. I don't have too many worries about Duensing pitching."
While some see it as a spot start for Duensing, assistant general manager Rob Antony said if all goes well, the decision could turn into a permanent role.
"He's making the start tomorrow and we'll see how that goes," Antony said. "If things go well, we'll keep it going, keep him in the rotation."
Duensing has never faced Cincinnati in his career.