BBC Sport - Serbia v Scotland Kris Commons and Russell Martin have not travelled for Scotland's World Cup qualifier in Serbia. Norwich defender Martin has a hamstring problem, while Celtic forward Commons is staying behind owing to what are understood to be personal reasons. Striker Steven Fletcher is unavailable to manager Gordon Strachan after damaging his ankle early in Friday's 2-1 defeat to Wales. And Robert Snodgrass is suspended following his red card at Hampden. Scotland sit bottom of Group A, without a win in five matches. The campaign opened with a drab 0-0 draw at home to the Serbs, with Craig Levein in charge of the hosts. Levein has since been removed from the post, with Strachan taking over in February. With qualification for Brazil 2014 out of the question, the focus shifts to vital ranking points and lifting squad morale. Scotland have recorded just three wins in their last 13 competitive games, two of which were against Liechtenstein. "We have spoken about the confidence being low," said Wigan playmaker Shaun Maloney. We know we have to improve to get anything out there and it's going to be very difficult. We just need to keep believing in the squad and hopefully this can turn round. Serbia have also had a disappointing run in Group A and Friday's 2-0 loss to bitter rivals Croatia left them just two points better off than Scotland. Defenders Nenad Tomovic and Milan Bisevac return from suspension but Manchester City full-back Aleksandar Kolarov serves a ban.