Clarke disappointed Scotland 'allowed Russia to dominate'
The Scotland boss says he's yet to determine why the side "dropped off" after taking the lead.
Steve Clarke admitted he doesn't yet know how Scotland let their lead slip as they fell to a 2-1 defeat against Russia and said he'll assess whether it was a mental problem that saw the team grow nervous and fall out of the game.
John McGinn had put the hosts ahead after just ten minutes but an equaliser from Artem Dzyuba came after sustained pressure from Russia.
A whirlwind start from the visitors after the break saw them create chances and Stephen O'Donnell scored an own goal under pressure from Yuri Zhirkov.
Clarke said that his side had shown the right attitude to get their noses in front then became inexplicably unsettled and invited the opposition back into the game.
"It was ultimately disappointing," he said. "I felt we had prepared well for the game and I think the start of the game shows you that we probably had.
"We got on top and got ourselves in front and then, for reasons I've yet to determine, we stepped off the game. We allowed Russia to dominate us and impose their style of play which is ultimately disappointing.
"It's something that we have to address and I think the biggest disappointment is that we gave the ball away quite cheaply. We seemed to become very nervous after we took the lead for some reason.
"Whether we thought we had to sit back and defend and see the game out, I don't know. Too many possession losses, too nervous on the ball and not enough threat going forward after the goal."
Clarke said he thought his side were going to be able to sustain the pressure and get back on top before the second goal but lamented the team defending that gave Russia their lead. And he admitted there was a lack of genuine punch up front with only a Charlie Mulgrew free kick worrying Russia in the closing stages.
"Russia started the second half better than we did, that's for sure, and put us on the back foot again," he said. "I thought we had weathered the storm and then lost possession and lost the second goal.
"A lot of players were out of position, getting caught on the halfway line. That was a really poor goal to lose.
"Towards the end we huffed and puffed a little bit but didn't really look like scoring, Charlie's effort excepted."
It was put to the manager that Scotland didn't have the quality in their side to properly test the bigger sides but he said that wasn't an issue and he would be looking to identify the problems before Scotland face Belgium on Monday in a game he says he needs to take something from if qualification hopes are to continue.
"If you look at the start of the game, we have good players," he said. "Why we allowed that game to drift away from us, whether it's a mental thing or a quality thing, we will need to assess."