Butland's initial stay with the Sky Bet Championship club was due to expire this week, but the England Under-21 international will now remain at the iPro Stadium for another seven days while Rams number one Lee Grant completes his recovery from an ankle injury.
The 21-year-old was brought in as cover for Grant after he was injured against Reading in October
Grant has missed six matches and it is still unclear whether he will be fit for Saturday's league trip to Watford.
Butland has made five appearances for Derby, keeping two clean sheets and helping the side to three wins along the way
Source : PA
Source: PA