The 30-year-old parted ways with the club earlier this year after making 117 appearances for Neil Reynolds’ side.
Potts successfully captained his side to the Fenix Trophy Final last year.
Taking to social media, he said: “[I’m excited to be back. I’ve missed being a part of FCUM and I feel grateful to be given the opportunity to play for this club again.”
The midfielder will be available for selection ahead of the Reds' clash with South Shields at Broadhurst Park on Tuesday night.
Keep up-to-date with our exclusive email newsletters.
Subscribe