The 20-year-old, who has considerable National League North experience from loan spells with Kettering Town, Chester FC and Chorley, has linked up with the Pilgrims as Ian Culverhouse shapes his squad for a new challenge in the National League.
He scored against the Pilgrims for Kettering in January 2023 - and was a regular starter for Chorley on their run to the play-offs at the end of the season just completed.
Maguire will officially become a Pilgrim on July 1 upon expiry of his contract at Bramall Lane.
Discussions are taking place with a host of prospective targets - with further updates to follow over the coming days.
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