Jake Bidwell will remain on loan at Brentford until 6 May.
The left-back, 19, joined the League One side in August on an initial one-month deal, with several extensions prolonging his spell closer to the business end of the season.
Currently lying fourth in the table, the Bees are firmly in the chase for promotion to the Championship – and Bidwell’s spell will take him through to the first leg of any potential play-off semi-final.
Everton’s Academy graduate spent much of last season on loan with Uwe Rosler’s side and has made 42 appearances this term.