Fournier and Olympiacos have agreed to a three-year contract, Eurohoops reports.
Fournier had 10 points (2-5 FG, 2-3 3Pt, 4-4 FT), one rebound and one assist in Friday's 85-71 loss to Germany.
The Pistons have declined to pick up Fournier's $19 million team option, James L. Edwards III of The Athletic reports.
Fournier (knee) is available for Tuesday's game against the 76ers.
Fournier (knee) is probable for Tuesday's game against the 76ers.
Fournier will not play in Saturday's game in Brooklyn due to right knee soreness.
Fournier accumulated five points (2-8 FG, 1-5 3Pt), four assists, three rebounds, one block and one steal over 29 minutes during Monday's 110-108 loss to the Grizzlies.
Fournier had a team-high 18 points (6-14 FG, 4-8 3Pt, 2-3 FT), four rebounds, one assist and three steals across 31 minutes off the bench during Sunday's 104-101 loss to Miami.
Fournier provided a season-high 17 points (6-13 FG, 3-8 3Pt, 2-2 FT), one rebound, five assists and one steal across 26 minutes off the bench during Sunday's 113-91 loss to Orlando.
Fournier logged seven points (3-5 FG, 1-3 3Pt), one assist and two steals in 20 minutes during Monday's 113-111 loss to the Knicks.