Derby County have sold teenage defender Dylan Williams to Chelsea - the fourth player the Rams have moved on in this transfer window.

Williams, 18, joins the Champions League holders for an undisclosed fee.

After making his debut aged 17 in last season's FA Cup third-round loss to non-league Chorley, Williams has made nine Rams first-team appearances.

His departure follows those of David Marshall, Phil Jagielka and Graeme Shinnie.

Williams is expected to figure in Chelsea's development sides in the short term.

Up-for-sale Derby sit second bottom of the Championship, eight points from safety, following Saturday's derby defeat by Nottingham Forest.

Placed in administration in September by former owner Mel Morris and deducted 21 points, Derby have so far battled hard against relegation to League One under manager Wayne Rooney.

But their main fight this season is to keep afloat - and avoid the growing threat of liquidation if they cannot conclude a deal to buy the club.

The wealthy US-based Binnie family, founders of investment company Carlisle Capital, submitted a bid of about £28m to buy the club on Friday.

But Derby's overall debts are reported to be more than double that - and that includes compensation claims from fellow English Football League clubs Middlesbrough and Wycombe Wanderers.

The club's administrators Quantuma had hoped to name a preferred bidder earlier this month, but they have to meet the EFL's statutory requirement for proof of how Derby will be funded for the rest of the season.