The 20-year-old has made 11 appearances and scored twice since arriving at Plainmoor and become a crucial cog in the Gulls side.
And Knill said that he has spoken to the striker's agent about extending his loan past the home clash with York on Saturday and all parties seem keen.
"I've spoken to his agent on Thursday morning," he revealed. "We need to speak to Derby and Callum. The two goals (in their 4-2 win over Cheltenham) will help him and that kicked his goalscoring off.
"We will get around to that but everyone seems very happy with it."
And while Knill tries to keep hold of his attacker he also has a defensive worry. Centre-back Aaron Downes has a potentially serious knee injury, suffering during a training session on Thursday.
He will now undergo an MRI scan but Knill is not hopeful about receiving positive results.