The person spoke on condition of anonymity Wednesday because the deal was still subject to a successful physical.
The 31-year-old Harrison spent his first eight major league seasons with the Pittsburgh Pirates. He’s played second base, third base, shortstop and in the outfield.
Harrison did not have a great 2018 at the plate, hitting .250 with eight home runs and 37 RBIs. He missed time early in the season with a hand injury and ended up playing just 97 games.
Harrison hit a career-high 16 home runs in 2017, and he batted .315 in 2014, but he’s never played more than 143 games in a season. If he plays well for Detroit, the rebuilding Tigers may be able to trade him for a prospect or two.
AP Baseball Writer Ronald Blum contributed to this report.