The 22-year-old, who bagged 20 goals as the Pilgrims earned promotion via the National League North play-offs last season, sealed a move back into the EFL with Accrington Stanley in the summer.
His game time has been restricted over recent weeks though and, having been an unused substitute at Anfield against Liverpool in the Emirates FA Cup at the weekend, Knowles now returns to the Jakemans Community Stadium on loan.
He is registered and eligible to feature against Southend United on Wednesday evening.
Make sure you snap up your tickets for the huge midweek encounter here.
PIC: Lee Keuneke.