|Slovakia v Scotland|
|Venue: Anton Malatinsky City Arena, Trnava Date: Tuesday, 11 October Kick-off: 19:45 BST|
|Coverage: Live on BBC Radio Scotland, online, mobile, the BBC Sport app, live text on BBC Sport website|
Scotland boss Gordon Strachan will prepare two teams for the World Cup qualifier in Slovakia as he waits for Darren Fletcher's fitness test results.
Strachan has had to alter his plans for the game in Trnava already.
The Slovaks changed formation and tactics since the Euro 2016 finals.
"I had ideas for two months what I was going to do, but suddenly they have dramatically changed their system over the last couple of games," Strachan told the media.
"We have had to have a real good rethink since Saturday night."
Slovakia, who lost 1-0 away to Slovenia on Saturday played "basically a 4-3-3, two wide-man" formation in France, said Strachan, whose captain has a thigh strain.
"I thought about that for the last couple of months - no wide men any more," he revealed.
"But Steven Pressley was out having a look at them, brought back great information.
"The players know that it has changed a bit, but we have to be on our toes, it might change again.
"We will prepare a team with Darren in and a team without Darren and put the final touches tomorrow. We are fine, looking forward to it."
Strachan expected to alter his starting line-up and tactics from the weekend anyway and will select a side that can adapt to whether Slovakia play three or four at the back.
He says he is happy with "three-quarters" of Scotland's performances in the two opening Group F games - the 5-1 win in Malta and the 1-1 draw with Lithuania - and he wants his side to take the "crosses, chances, excitement" from the second half at Hampden on Saturday into Tuesday's game.
Strachan expects a different challenge, though, against a side that has yet to score or pick up any points from their World Cup qualifying campaign, despite being the second seeds behind England.
"The ball won't be going so long, we joined in as well, not just Lithuania," he said.
"We try every time to win the game, there is absolutely no doubt about that. It is very rarely you see us going for a draw."
Despite dropping two points at home to Lithuania. Strachan remains confident that Scotland can challenge for second place in Group F - and be in the mix for the play-offs.
"It is a strange, strange group and, the stranger it gets, the better for us," he said, pointing out that the Scots are third seeds in the section. "So, if we end up at two at least, we will be delighted at that.
"I don't know how many qualifiers England have played with very few defeats, if any. I think most of us expect, the footballing world, that England would win it.
"We will definitely go and try and get second at least and if we end up getting first then great. But second is our target as we sit here."