Carter agreed to a deal with the Celtics on Monday, Michael Scotto of HoopsHype.com reports.
Sasser will compete for playing time off the Mavericks' bench in 2026-27, and he could operate as the primary backup to Kyrie Irving (knee).
De Larrea ended with nine points (3-5 FG, 3-3 3Pt, 0-1 FT), two rebounds and one assist in 11 minutes during Spain's 108-106 loss to Greece in Tuesday's FIBA World Cup qualifier.
Queta could take an offensive leap in the 2026-27 campaign after averaging a career-high 10.2 points per game last season, Jack Simone of BostonSportsJournal.com reports.
Aldama (knee) is expected to be ready in time for training camp, according to NBA reporter Marc Stein.
Mitchell is likely to serve as emergency depth for the Celtics in his rookie season.
Cenac appears to be buried on the Celtics' depth chart ahead of his rookie season.
Johnson enters his rookie campaign after Dallas selected him ninth overall in the 2026 NBA Draft.
Gonzalez has a chance to claim a larger role in 2026-27 after the Celtics traded Jaylen Brown to the 76ers in exchange for Paul George.