Former Chelsea striker Mateja Kezman claims the Blues would not have lost their Champions League quarter-final first leg against Fenerbahce if Jose Mourinho was still in charge.
The Serbia forward spent a year at Stamford Bridge three seasons ago under Mourinho, winning the Barclays Premier League title and Carling Cup, before moving on to Atletico Madrid and then Fenerbahce.
Mourinho's successor Avram Grant has been under pressure because of his failure to win important games, with Wednesday's 2-1 defeat in Turkey the latest example.
Kezman told the Daily Mail: 'Under Mourinho, Chelsea were a machine - and they worked for 90 or 95 minutes without mistake or faults.
'If Mourinho had been in charge of this match, of course it would have been different.
'He's a very different coach, and in his time there were no surprises and no mistakes. Everything worked fantastically. They don't have the same spirit in the team any more.
'We are full of confidence for the second leg. We will not show as much respect for them in London.'