Mackanin was hired by the Cincinnati Reds as a scout for the 2007 season, but when the team fired manager Jerry Narron on July 1 of that year, he was named the club's interim manager. Narron had led the Reds in the first half of the 2007 season to a league-worst 51 losses, but during Mackanin's tenure, the team had a winning percentage above .500. The Reds decided not to hire Mackanin on permanently for the 2008 campaign, instead deciding on veteran experience with Dusty Baker.