Wednesday 2 September 2015 11:13, UK
Derby added teenage goalkeeper Devlin Mackay to their development squad ranks on transfer deadline day.
Mackay made the move south of the border from Scottish Premiership club Kilmarnock on a loan deal until January.
The 18-year-old is expected to feature for Darren Wassall's development squad in the Barclays Under-21 Premier League Division Two.
Devlin, a Scotland youth international, has yet to make his first-team debut for Kilmarnock.
He played a trial match for Derby last week when they beat Burnley 3-2 in a friendly at the Rams' training ground.
Meanwhile, Kelle Roos is back with Paul Clement's side after his season-long loan spell with Sky Bet Championship rivals Rotherham was ended prematurely on Tuesday.
