Latest: Derby County 0 Chelsea 0
Eden Hazard is on for Chelsea at Pride Park, where Oscar almost put them ahead in an even first half and Ramires hit the Derby post just before the interval.
Oscar sent a free-kick narrowly wide and went close with two other decent strikes during a spell of Blues pressure.
Ramires also fired wide for the visitors after in-form Championship side Derby had made a determined start to the FA Cup third-round clash.
Ashley Cole did well to clear a dangerous early cross from Jeff Hendrick before David Luiz blocked a driven shot from Rams midfielder John Eustace.
Luiz is alongside Gary Cahill for Chelsea, as captain John Terry is on the bench.
And Cahill was called into action following a 28th-minute error by Luiz, who lost possession and was grateful to see his centre-back partner block Jamie Ward’s shot.
Seven minutes before the break Eustace had an effort saved by Mark Schwarzer after the ball was given away again, this time by Ramires, whose deflected shot clipped the woodwork moments before the half-time whistle.
Chelsea made a lively start to the second half and boss Jose Mourinho made a statement of intent on 55 minutes, bringing Hazard on for stand-in skipper Michael Essien.
The winners of the tie will be at home to Stoke City in the fourth round.
Chelsea: Schwarzer; Azpilicueta, Cahill, Luiz, Cole; Essien (Hazard 55), Mikel; Ramires, Oscar, Willian; Eto’o.
Subs: Cech, Kalas, Terry, Baker, Mata, Torres.
Follow West London Sport on Twitter
Find us on Facebook