Marrs and Mitchell head out to gain experience.
Two of Sunderland's development squad players have completed loan moves.
Defender Liam Marrs (pictured) and winger Adam Mitchell have joined Skrill North sides Boston United and Harrogate Town respectively.
Marrs, 20, has joined the fourth-placed Pilgrims on an emergency loan until January 1 and could make his debut against Brackley Town this weekend.
The right-back has been at Sunderland since the age of 12 and has made eight league appearances for the development squad this season.
Meanwhile Mitchell has penned a youth loan with Harrogate until November 30 and is in line to face Oxford City at the CNG Stadium tomorrow.
The 20-year-old has made one first-team appearance for Sunderland - against Tottenham Hotspur in the final game of the 2012-13 season.