The 33-year-old centre-half, who enjoyed a stunning two-year spell with the Pilgrims between 2009 and 2011, has re-joined the club on loan from Grimsby Town, whom he has twice helped to promotion to the EFL.
He scored 20 goals in 78 appearances during his first spell with the Pilgrims – and has added over 400 senior appearances since for the Mariners and Wrexham.
Pearson will wear squad number 26 on his return to United – and is eligible to make his homecoming against Leamington on Saturday.