Steve McClaren says Leicester will provide Derby County with a gauge of their Premier League credentials when the teams meet in the FA Cup.
The east Midlands rivals are fourth round opponents at Pride Park in an encounter McClaren believes Leicester will treat like a Champions League tie.
Derby have risen into Championship play-off contention since McClaren's return in October and beat West Bromwich Albion in the last round.
Promotion to the Premier League is the club's primary aim and for all Leicester's struggles McClaren insists the strength of opposition will be valuable.