Brentford have extended John Swift's loan deal with the club until January 3.
The 20-year-old midfielder arrived at Griffin Park last month from Chelsea on an agreement that was due to run until early December.
However, having made four Championship appearances since then, the Bees have moved to tie Swift to the club by a further four weeks.
"We are delighted that Chelsea have allowed John to stay with us until January. He has been a very good addition to the squad. He has slotted in well to the group," head coach Lee Carsley told the club's official website.
"We spoke to him about pushing on and standing out with the quality he has. It is important he doesn't rest on his laurels.
"His workrate has been outstanding since he has been with us and if he wants to stay in the team he has to maintain that."
Swift scored his first goal for Brentford during Saturday's 3-0 victory over Charlton Athletic.
