Prince, an unrestricted free agent, has spent his entire career with the Pistons since coming into the league in 2002. The veteran swingman averaged 14.1 points in 78 games last season.
The deal cannot be formally completed until Friday, when the league opens training camps.
According to The Associated Press, Jonas Jerebko also will be back with Detroit, on a $16 million, four-year deal. Jerebko is a restricted free agent.
The Pistons have been working out at the team's practice facility in Auburn Hills, Mich., for a week since lockout restrictions were lifted by the league. They have a lot of work to do, coming off a 30-52 season that led to the firing of coach John Kuester.
New coach Lawrence Frank will have a veteran at small forward in Prince, who could've chased another NBA championship ring with another franchise. Prince averaged 14.1 points last season, his ninth with the Pistons.
Detroit drafted him 23rd overall out of Kentucky in 2002 and he helped them reach at least the Eastern Conference finals in his first six seasons. The 6-foot-9, 215-pound Prince has been regarded as one the better defenders in the league and has averaged nearly 13 points over his career, but he has had three straight down seasons.
Jerebko appears to be ready to play after missing all of last season with a torn right Achilles tendon. The 6-foot-9, 215-pound Swede played in a team-high 80 games as a rookie two years ago, averaging 9.3 points and six rebounds.
The Pistons selected Kentucky guard Brandon Knight No. 8 overall last summer, potentially adding to their glut of players on the perimeter with shooting guards Richard Hamilton and Ben Gordon. They got plenty of production out of last year's first-round pick, center Greg Monroe, who was drafted No. 7 overall.
Ric Bucher is a senior NBA writer for ESPN The Magazine. Information from The Associated Press was used in this report.