The 21-year-old attacker has had limited first team opportunities at The Valley and been loaned out to Torquay, Colchester and Cheltenham Town in recent seasons.
MacDonald is now set to try his luck in Germany with recently-relegated Pauli who are keen on bolstering their squad for the promotion push next term.
The striker will hope to impress coach Dietmar Demuth and win himself a move to the German Second Division.
