Some slick play down the right gets Nathan Byrne into space and his first-time cross looks to cause some problems but it's whacked away.

Posh are dropping deeper under the pressure but are getting a toe to everything.

There's more energy in midfield for Derby now. Louie Sibley gallops down the left and slides a tantalising ball across but Jack Stretton cannot connect.

Frankie Kent puts himself in the way as Derby really push for the opener, and Ravel Morrison gets a couple of cracks at goal.

The Posh defence just about clinging on there.

Rams might just be edging ahead in the momentum stakes.

Image source, Rex Features

Thumped away by Posh as Tom Lawrence skips down the left.

Now Louie Sibley has put a tackle on Dan Butler that leaves the Posh defender limping.

Great cross to the back-post which is headed down by Jonson Clarke Harris. Posh can't finish.

Then Nathan Thompson gets a booking for clipping the heels of Louie Sibley as he drove at the heart of the Posh defence on the counter.

Couple of Posh set-pieces cause some problems but just can't get a clean connection.

Siriki Dembele is back in the frame off the bench, replacing Jack Marriott.

Posh get the ball into the box from the right, but it's taken coolly by Kelle Roos.

Derby look a bit shaky at the back, Roos' distribution not perfect, but they survive and break through Tom Lawrence, but the final ball no good.

Festy Ebosele is replaced by Louie Sibley.

Still no breakthrough here, as the second half has suffered with a stop-start rhythm.

Tom Lawrence has continued, but Louie Sibley is getting ready on the bench.

Derby might be switching things up shortly.

Ominous signs now for Tom Lawrence, who goes down under a challenge. Looks a painful one.

And another key figure is in trouble.

Colin Kazim-Richards is withdrawn on a stretcher, a nightmare start for the Rams in this second-half and on comes Jack Stretton.

He's only 19.

Innocuous injury for Kazim-Richards, pulled up chasing a ball to the byline.

Image source, Rex Features

Back under way in Cambridgeshire and Jorge Grant gets away an early long-range strike for Posh.

Comfortable for Kelle Roos in the Derby goal.

It's been a game of half chances so far.

Image source, Getty Images

Just the two shots on target in that first half - one apiece.

Must do better.

Aside from Peterborough-Derby, which is currently 0-0 at the break, these are the rest of today's Championship fixtures.

All 15:00 BST unless stated.

• Barnsley v Coventry City
• Birmingham City v Stoke City
• Blackpool v Cardiff City
• Huddersfield Town v Fulham
• Hull City v Queens Park Rangers
• Middlesbrough v Bristol City
• Millwall v Blackburn Rovers
• Nottingham Forest v AFC Bournemouth
• Reading v Preston North End
• West Bromwich Albion v Luton Town
• Swansea City v Sheffield United [20:00 BST]

I can't say I'd like to be a Sheffield United fan travelling back from Swansea at about 10 o'clock tonight.

Honours even at the break.

Peterborough have looked lively up top with Jack Marriott, Jonson Clarke-Harris and Joel Randall involved.

At the opposite end, Derby haven't really tested Christy Pym but they've enjoyed much of the possession and in Ravel Morrison and young Festy Ebosele, they've got threats too.

Just need some goals now. And Posh can score them. Eighty-three last year.

Image source, Rex Features

Posh went direct and almost find Jack Marriott, but he just can't get his toe on it and it goes to Kelle Roos.

The forward just maybe lacking that extra sharpness.

Dan Butler crosses but Richard Stearman gets his nut on it. Cleared.

One minute added time.

Tom Lawrence curls harmlessly into the box and beyond for a Peterborough goal-kick.

Festy Ebosele has been involved in everything good that Derby have done so far, but chances have been hard to come by.

They've had plenty of ball, the Rams.

Graeme Shinnie and Ravel Morrison combine, Derby get a free-kick for Oliver Norburn's snapping challenge.

Chance here. Half-time looming.

Posh play through the lines and Joel Randall spots a nice diagonal to put Joe Ward in on the right but the referee's assistant has the flag up.

Offside.

Very close though. Randall looks to have the vision. Get that timing right and Ward is in on goal.

Jonson Clarke-Harris goes after a high ball on the left and leaves his arm on Nathan Byrne for Derby.

Goes down. Free-kick.

The Rams pass it rather than shoot, Tom Lawrence cuts in from the left and looks like he's clipped but Joe Ward gets on with it and plays to the whistle.

Posh break but the final ball is not good enough and now some concern for midfielder Jorge Grant, who is down injured.

Jonson Clarke-Harris hits a 40 yarder out of nothing and Kelle Roos in the Derby goal is almost outfoxed before managing to sort out his feet and just about block it.

Clarke-Harris was given the time and space and whacked a shot which moved about before it was saved - almost unorthodoxically - by Roos.

Image source, Rex Features

Festy Ebosele races down the right and the pass tracks him beautifully.

The Rams wide man takes on Mark Beevers but the Posh defender stands his ground and forces him behind.

Goal kick. Ebosele shows his frustration but it was cleanly done by Beevers.

Good tussle that one.