Tottenham defender Younes Kaboul is likely to miss the majority of his side's race for fourth spot following an injury in an Under-21 match.
Kaboul sustained a serious knee injury during Tottenham's opening day of the season clash against Newcastle and was looking likely to make a return to the first team later this month.
However the French defender played just 48 minutes of the reserve tie at the Salford City Stadium before being replaced by Jack Barthram after suffering yet another injury scare.
Villas-Boas had hoped Kaboul would be available for their clash with Manchester City on Sunday following William Gallas' injury to his calf during their Europa tie against Basel.
The Portuguese manager said at the start of the month: "Injuries come at bad times, but most of the players who are out should only miss a couple more games."
Despite Kaboul's setback, Tottenham's defensive injury crisis looks to be diminishing with Michael Dawson, Jan Vertonghen and Steven Caulker all returning to full fitness.