Mauricio Pochettino admits he does not know exactly when Chelsea goalkeeper Robert Sanchez will return from his knee injury.
Pochettino has revealed Sanchez is certain to miss the next few weeks after suffering an injury earlier this month.
The £25million summer signing underwent a series of medical tests last week but it is still unclear how long he will be sidelined.
Sanchez initially sustained his injury away at Manchester United but played though pain at Everton before he was forced off late on at Goodison Park.
Djordje Petrovic made his first Chelsea start in Saturday’s 2-0 win over Sheffield United.
Speaking ahead of Tuesday’s Carabao Cup quarter-final against Newcastle, Pochettino said: “It is an injury that’s going to be for a few weeks, I don’t know if two, three, four, five or six.
"We will assess day-by-day to know how to follow it. His recovery will depend on him and the reaction of his knee and it is difficult to say in two or three weeks but we hope [he is back] as soon as possible."
Like Sanchez, Chelsea aptain Reece James continues to be assessed but defender Marc Cucurella has had surgery after suffering an ankle injury away at Everton.
Winger Noni Madueke could return from a minor muscle injury against Newcastle but Chelsea will be without nine players on Tuesday night.
