The Jazz waived Preston (calf) on Wednesday, Tony Jones of The Athletic reports.
Preston (personal) will be a full participant in training camp, Andy Larsen of The Salt Lake Tribune reports.
Preston (personal) has been ruled out for Sunday's Summer League matchup against the Pistons.
Preston is out for Thursday's Summer League game versus the Clippers due to personal reasons, Ben Anderson of KSL News Salt Lake City reports.
Preston chipped in six points (3-6 FG, 0-1 3Pt), four rebounds, six assists and one steal across 17 minutes during Friday's 131-102 loss to the Clippers.
Preston was waived by the Grizzlies on Wednesday.
Preston signed a one-year contract with the Grizzlies on Monday.
Preston tallied 13 points (5-13 FG, 0-1 3Pt, 3-3 FT), 10 rebounds and five assists in 27 minutes during Wednesday's 83-74 Summer League win over the Clippers.
Preston finished with 16 points (6-17 FG, 2-8 3Pt, 1-1 FT), five rebounds and one assist in 29 minutes during Monday's 108-101 loss to the Memphis Hustle.
Preston finished Sunday's 122-99 loss to the Cavaliers with 12 points (6-12 FG, 0-3 3Pt), eight assists, three rebounds and one steal in 37 minutes.