Scotland manager Steve Clark admits Arsenal left-back Kieran Tierney is key to their hopes of success.

The Scots were left unprepared as Tierney was ruled out of their opening group game against Czech Republic.

After losing the game 2-0, Clarke admits a lot of the tactical work they did pre-match focused on having Tierney bombing down one flank.

Scotland face bitter rivals England in their next group game on Friday.

"Obviously we'd done a lot of work on team shape and Kieran was involved in that," said Clarke.

"With 48 hours to go when he picks up the little niggle that kept him out, it does take a little bit of changing, it changes the dynamic of the team.

"Kieran has been an integral part of how we have played recently but I don't think we defended too badly.

"The moments in the game that got away from us; the first one is preventable, the second is really good."