The 18-year-old suffered suspected knee ligament damage just seconds into the 1-0 Barclays Premier League defeat at Manchester United, and manager Steve Bruce's comments in the immediate aftermath of the game were far from positive.
Former Ipswich frontman Wickham, who joined the Black Cats for an initial ?8.1million during the summer, was expected to discover later that day just how bad the damage is.
Should he be sidelined for some time, that would leave Bruce with just two fit specialist strikers - loan signing Nicklas Bendtner and South Korea international Ji Dong-won.
However, it is understood there is no chance of Asamoah Gyan being recalled from his season-long loan spell at Al-Ain in the United Arab Emirates.
Gyan made his shock move to the Middle East in September after a less than impressive start to the new campaign, and an unhappy Bruce initially admitted it was difficult to see him returning.
Fraizer Campbell was given good news by his specialist last week when he was told he was three months ahead of schedule in his recovery from a knee injury, although he is unlikely to be fit until the new year.
Saturday's defeat left the Black Cats just one point clear of the relegation zone, and they face two huge home games after the international break.
Fulham and Wigan visit the Stadium of Light on successive weekends and Bruce's men desperately need a maximum return if they are to kick-start their faltering season.
However, if they are to do so, they will have to do it - for the first game at least - without midfielder Sebastian Larsson, who collected his fifth booking of the campaign at Old Trafford and will be suspended against Marton Jol's side.
Source: PA
Source: PA