MILLWALL have an option to extend Jamie Philpot's contract – but the club have yet to decide if they will take it up.
Philpot, 21, is currently on loan at National League side Woking until January 2.
The forward signed a two-year deal in the summer of 2016 after making his debut at the end of the 2014-15 season when he scored with his first touch in senior football at Wolves.
An injury picked up in the same game kept him out for a number of months and Harris admitted that and inconsistent form has contributed to limiting him to just 12 senior Millwall appearances.
He has scored five goals in his last 10 games, including one in Woking's shock 3-0 win in their FA Cup first-round replay win at Bury on Tuesday.
Harris has been impressed with Philpot's form at Woking and urged him to sustain it to be in with a shot of earning a new deal.
"Jamie has had a tough couple of years, a disappointing couple of years," Harris said. "Young players progress and stutter at different stages of their careers.
"Jamie had a great progression between the ages of 16 and 18 and then stuttered the last couple of years through injury and lack of form.
"He's gone out on loan to learn the game, to learn in some ways how fortunate he, as one of the younger players at the club, is to be involved here.
"He's done well but there is a long way to go.
"In terms of contracts for the youngsters, some will be sorted out before others. Jamie is one who has just got to get his head down and work hard. Doing it for a couple of months doesn't make a career.
"We've been really impressed with him over the course of the last six or seven weeks.
"He's got to keep doing that for a sustained period before we make a decision where his future lies."
Image: Woking FC