Wales Assistant Manager John Hartson says his side must improve following a dismal performance against Serbia last month.
Wales lost 6-1 to their rivals and suffered an enormous setback in their bid to reach the 2014 World Cup.
John Hartson told journalists: "It wasn't good enough."
The Wales squad will sport pink ribbons on their tracksuits at the World Cup qualifier tonight in support of April Jones's family.
It has now been more than a week and a half since the five-year-old went missing from her home in Machynlleth.