The Holland Under-21 international, on loan from Chelsea, suffered the injury during the 1-1 home draw against Midlands rivals Coventry on Saturday.
Manager Sven-Goran Eriksson admits losing Van Aanholt is a blow, but the Swede believes his squad is strong enough to cope with the 20-year-old`s absence and he will not be scouring the loan market for a replacement.
"Patrick is out for three or maybe four weeks," Eriksson told the club`s official website. "That is a pity, of course, as he has been very good for us but I am not looking at loans for defenders at this moment.
"We have options. Bruno Berner is a left-back and Kyle Naughton has played at left-back in the past. We could also use Miguel Vitor and Ben Mee can play there as well."
Van Aanholt, whose loan deal runs until the end of the season, will remain at the Walkers Stadium during his recovery period.
Source: PA
Source: PA