Chelsea boss Thomas Tuchel cannot put a set date on N'Golo Kante's return.
For the draw against Tottenham Hotspur (2-2), the France international suffered a thigh injury and had to be substituted.
Tuchel was asked for an update on Kante during Friday's presser ahead of facing Leeds.
He said: "We are talking about weeks here, which is not good news. We are disappointed and sad because N'Golo was super fit."