"I'm not being critical of the individuals concerned. Our defence is organised and disciplined and James has made some great saves.
"But I watched Portugal play Spain the other night and Scolari put three Portuguese players on the halfway line when defending against corners. This meant Spain had to withdraw four players to mark them.
"I know it's not the same at Motherwell but I always have two players on the halfway line when we're defending a corner. This means your opponents have to cover them with three men. This dilutes the attacking threat.
"If England have everyone back in the box defending at set-pieces it allows their opponents to fill the box with bodies. It's so crowded that our defenders have difficulty staying with the man they're marking and the goalkeeper has difficulty coming forward to attack the ball.
"It also means if you do clear the trouble there's no one upfield to receive the ball. It simply comes straight back at us.
"If we keep two players upfield, the opposition must mark them with three. One takes the kick, one's in goal, one sits on the edge of the penalty area. That means they can have only five in the box at corners.
"The fewer players in the box the more chance your goalkeeper has of catching the ball or punching it clear.
"No one has scored against us in open play so if England can stop conceding sloppy goals at set-pieces they're playing well enough in other areas to really make a big impression in this tournament."
