Derby bolster youth ranks with signing of Devlin Mackay

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.