The 33-year-old defender joined Farnborough in June this year, after spells in The Vanarama National League Captaining Eastleigh and Aldershot Town.
From the start of August to the end of September, Parts made 13 appearances for Boro in all competitions, scoring once in The Emirates FA Cup.
Manager Spencer Day added:
“We thank him for his time with us and wish him every success (although perhaps not this weekend!).”
View the updated Squad list.