Glenn Murray
Former Brighton striker on BBC Two

That professionalism, training every day and fitness is just starting to show through from Doncaster.

It looks like Billy Sharp might have just dragged his team through single handily.

These Blues substitutions were already on the cards before the Rhodes goal but having seen what Blackpool's have done, there's a bit more pressure now.

Ayumu Yokoyama, Lukas Jutkiewicz and Brandon Khela are off as usual suspects Keshi Anderson, Alfie May and Paik Seung-ho come on to restore some stability.

The second half of extra time begins. Can Kettering dig deep here?

Lewis Wing is causing plenty of trouble for Harborough who are sitting in a deep block formation.

But Riley O'Sullivan wins a free kick to give his defence some respite and it is a yellow card for centre back Abraham Kanu.

It is going to be a long match now for Kanu on a caution and a knife edge.

Corner for Harborough now.

Doncaster are ahead at the break in extra-time.

A perfect time to score for Rovers and a gut-wrenching goal to concede for Kettering just moments before the interval.

Can they rescue this tie in the last 15 minutes now?

Former Spurs and Brazil international Sandro makes his first significant intervention with a crunching tackle on Ashqar Ahmed. That brings him into the game and gets a huge cheer from the travelling support.

Those half-time changes are paying off!

Jordan Rhodes' header doesn't have much pace but it's in a deadly position and has to be cleared off the line by Taylor Gardner-Hickman.

Meanwhile goal scorer Lyndon Dykes is awarded Blues' fourth yellow card, much to his bemusement.

Kettering's players are definitely starting to look a bit leggy. This is a huge final 15 minutes or so for them.

Troy Deeney
Former Watford striker on BBC Two

What a clearance!

Lewis White is struggling and is feeling the pace but he keeps going and he doesn't quite on his team.

If he doesn't keep going and quits then that's a goal and Kettering are in serious trouble of going out of this competition.

Excellent defending from the big man.

Elliott Taylor with a good tip to deny Lewis Wing for a second time. A dipping effort was heading just under the bar well dealt with by the Harborough stopper.

Kettering continue to stand firm but they are under some consistent Doncaster pressure now.

You'd imagine Rovers will not want the lottery of penalties against their seventh-tier opposition.

Image source, Getty Images

Young and hungry Reading side are making the men in yellow run around... a lot.

An average age 20 years and six months for Ruben Selles's side may be lacking experience but it does not lack pace.

A Harborough free-kick awarded just outside the area gives them some breathing space.

What a clearance this is by Lewis White for Kettering!

Doncaster's Luke Molyneux gets on the end of Billy Sharp's clipped ball to the back post but White is there to block it on the line!

He's prevented a certain goal there.

Doncaster get forward down the left and there are plenty of bodies in the area but they can't find a blue shirt.

Kettering can clear but Rovers are coming back again.

Lots of noise from the visiting fans but Reading are starting to get a grip of the opening exchanges.

Reading with all the ball and Harborough being forced to sit back and absorb the pressure.

Elliott Taylor forced into a fine save after Lewis Wing pings a shot goalward.

A bit of a scrappy opening to extra-time as you might expect. Some pinball in midfield as both sides look to try and get a foothold.

Ball not spending too much time in play.

Image source, Rex Features

Big call made by Steve Bruce at the half-time as he introduces a quadruple change for the second half.

Elliot Embleton, Ryan Finnigan, Dom Ballard and Kyle Joseph are out of the fray.

Josh Onomah, Dominic Thompson, Ashley Fletcher and the ever threatening Jordan Rhodes are on to try to turn the tide.