Dundee United are sweating over the fitness of their Ghanaian midfielder, Prince Buaben ahead of the Scottish season.United manager Craig Levein is keen to establish what is currently hampering Buaben's fitness after he lasted just 40 minutes of the team's pre-season friendly win over Stirling Albion on Saturday.Initial concerns were that the 21-year-old had contracted malaria while on holiday in Ghana, although tests have now ruled out that possibility.But Levein is keen to establish the cause of the illness sooner rather than later."Prince has been suffering from a virus and we need to get to the bottom of it," explained Levein."He's had his blood taken and nothing major seems to be showing up. He was in Ghana over the summer, so we were a bit worried it might have been malaria or something."But he's been checked out and thankfully it's not that. It's a worry, but we'll just have to see how he is this week."Source: ghanafa.org