Gianfranco Zola was absent from the Chelsea bench for a second successive match after being readmitted to hospital following gallstone surgery complications.
Zola, assistant to Blues head coach Maurizio Sarri, missed Monday's FA Cup loss to Manchester United and was again absent for Thursday night's Europa League last-32 second leg with Malmo.
There is no timescale for the return of the 52-year-old former Chelsea player, whose absence could be keenly felt by Sarri, with the 60-year-old's position precarious.
Zola could be an option to succeed Sarri, at least on an interim basis, if the Blues boss is sacked due to poor recent results.
Gallstones are when a crystalline mass forms in the gallbladder and can be painful and cause blockage of the bile duct.
ga('create', 'UA-72310761-1', 'auto', {'name': 'pacontentapi'});
ga('pacontentapi.set', 'referrer', location.origin);
ga('pacontentapi.set', 'dimension1', 'By Press Association Sport staff');
ga('pacontentapi.set', 'dimension2', '8e133310-8dbe-412a-b508-75d539c57e2c');
ga('pacontentapi.set', 'dimension3', 'paservice:sport,paservice:sport:club-news,paservice:sport:football,paservice:sport:uk');
ga('pacontentapi.set', 'dimension6', 'story');
ga('pacontentapi.set', 'dimension7', 'composite');
ga('pacontentapi.set', 'dimension8', null);
ga('pacontentapi.set', 'dimension9', 'sport:football');
ga('pacontentapi.send', 'pageview', { 'location': location.href, 'page': (location.pathname + location.search + location.hash), 'title': 'Zola misses Chelsea\u2019s Europa League clash through ill health'});