The former Portsmouth left-back joined the Lions on loan in January but has yet to feature in the first-team picture at The Den, due in part to a troublesome back injury.
However, Jackett has also revealed that Sowah's parent club would be entitled to a loan fee should he make an appearance, and that his inexperience of the Championship has also counted against him.
"The deal is that if we play him we then have to pay for him," he told Lions Live. "Up until that point we can have a look at him until the end of the season.
"He's 19-years-old and I do think he's got some potential, but I am very cautious of that trigger and the position that we're currently in. In other circumstances, and if we win a few games and we're in a safe position, things may change.
"You do need to speculate and have a look at people. I can remember him before he went out to Hamburg and back then he was a very promising left-back."