The Pilgrims have clinched the season-long loan signing of 22-year-old Altrincham striker Zak Goodson – who made one appearance on loan in October, before sustaining a broken wrist on the final whistle against Chester FC.
Goodson is now back to full fitness and played and scored in last week's Isuzu FA Trophy victory over Wrexham.
Gateshead midfielder Lirak Hasani, meanwhile, has joined the Pilgrims on loan until the end of the season.
The 20-year-old playmaker made 11 senior appearances for Doncaster Rovers earlier in his career and has since enjoyed loan spells with Matlock Town and Basford United.
Goodson will resume his United career in the number 19 shirt, while Hasani will wear 32.
Meanwhile United's National League North trip to Southport will now take place on Tuesday March 14 (kick-off 7.45pm).
Twice postponed due to inclement weather, on December 10 and January 17, the two clubs will now attempt to play the outstanding fixture at the third attempt.
The new date falls outside the National League's 42-day re-arrangement window as the next available date – due to Southport's impending run of midweek National League North and County Cup fixtures.
Ranging from Scarborough Athletic on Saturday January 28 to AFC Telford United on the final day (Saturday April 29), all fixtures can be purchased.
Car parking is also on sale for the 3pm kick-offs – and only unavailable for the midweek fixtures against Brackley Town and Spennymoor Town, due to existing bookings on the 3G pitch.
United edged an eight-goal National League U19 Alliance thriller against Darlington.
The Pilgrims led 1-0 and 3-1 - but Darlington were back on terms at 3-3 by the 68th minute. Two quickfire goals from Jack Waddington and Owen Sheriff sealed Boston's victory.
United's first half goals came courtesy of Han Stevens and a brace from Oskar Rajski.