Adriana Leon does indeed come on, Melissa Tancredi the player to make way.

Looks like John Herdman is about to throw on another striker. He is chatting with Adriana Leon. Despite all their possession, Canada have not actually made Siobhan Chamberlain work since coming on.

Image source, Getty Images

Just over 20 minutes left for England to make history and reach the semi-finals. 

Mark Sampson has made some astute substitutions at this tournament, and he could probably do with pulling some out of the bag again now. England are looking a little tired and more than a little nervy. 

Jade Moore gives away a free-kick on the edge of the England area after a foul, picking up the game's first yellow card. It is shooting territory for Christine Sinclair, but she curls the ball over.

A change for Canada as midfielder Diana Matheson replaces Rhian Wilkinson.

I spoke too soon. Panic in the England defence as Melissa Tancredi has the ball, no-one puts a foot in and she looks certain to shoot but inexplicably dithers too long and finally someone takes control and clears.

It is not just Siobhan Chamberlain's first game at this World Cup, apparently it is her first at any World Cup.

At the moment, her colleagues are doing a solid job of keeping Canada away from the England area.

There's another big mistake in this isn't there? 

From the corner, Canada cannot clear and the ball eventually falls to Steph Houghton, but her shot is charged down. All very tense now.

Image source, Reuters

Superb save! Sophie Schmidt gives the ball away to Karen Carney and she runs into the area. She looks a little unsure what to do next, before playing it short to Jodie Taylor, who shoots and Erin McLeod produces a stunning one-handed save to push the ball behind. Top stuff.

Siobhan Chamberlain has barely had time to warm up but she is on now for Karen Bardsley and straight in at the deep end. Never straightforward with England is it?

What's happened here? England keeper Karen Bardsley is down on the ground, indicating a problem with her eye. She can't continue, it is quickly swelling up, and Siobhan Chamberlain is going to have to come on here.

Good, positive start to the second half by England as Katie Chapman quickly feeds a pass to Karen Carney, who lets fly with a shot from 30 yards that lands on the roof of the net.