McGowan has spent the early portion of the season on loan at the Pilgrims and the Reds have agreed to the central defender making the loan into a permanent switch.
A powerful young central defender, a former Notts County trainee, joined the Reds from Grantham Town in December 2015.
He quickly settled into life in National League North with some man-of-the-match performances, Strong and brave in the air, he reads the game very well and commands his back-line.
He captained the Notts County under-18 side, during the 2013/14 campaign in which he also impressed in their development squad, which saw him rewarded with a professional contract.
A freak hand injury during the 2-0 win at Curzon Ashton in February, ruled him out of the rest of the 2015/16 campaign.
Last season 2016/17 saw McGowan become a model of consistency, he made forty-eight appearances for the Reds, scoring one goal and scooped the Reds player of the year award.
McGowan has featured during pre-season but has yet to make an appearance in the 2017/18 campaign.
Reds manager John McDermott: “For Brad he didn’t want to be sat on the bench, his goal is to get into the football league and be playing in the football league.
“He wanted to start games and unfortunately we couldn’t guarantee that. He’s a great player and he would have been in my sixteen. It’s a tough decision but it’s for his best interests. His attitude has been excellent, I have enjoyed working with him and he’s a lovely lad.
“Obviously with Billy Priestley and Luke Shiels, Brad would be my cover for those two and he can’t be sat on the bench, he wants to start games.”
“I wish him all the best, it’s been a tough call but his interests come first, he is a great professional and I wish him all the best at Boston”.