Ronald Koeman has credited Guus Hiddink with rebuilding Chelsea's shattered confidence following the departure of Jose Mourinho and believes the influence of Hiddink is the reason for the Blues' improving form.
Chelsea visit Southampton in the Premier League on Saturday having experienced defeat only once since Hiddink's arrival in December, following a traumatic opening half to the season that led to Mourinho's sacking and in which he frequently criticised his players.
Koeman's team have similarly improved after a poor run, and the Dutchman -- who is familiar with Hiddink's methods having been coached by him at PSV Eindhoven -- revealed he expected the impact his compatriot would have.
"He is always defending his players and that is good for Chelsea at that moment,'' said Koeman. "He was the right man at the right moment and the players are looking more comfortable and he has given them confidence. I was expecting that because they have good players with good qualities.
"The way the manager is dealing with the team is good for this moment. He is a coach with a lot of experience at all levels and knows a lot. He has a knowledge about characters of players and how to give them that important support to the key players.''
One individual who has particularly thrived since Hiddink's interim appointment is Diego Costa, who had struggled under Mourinho earlier in the season, despite having contributed significantly to Chelsea winning the league last year.
Southampton have not conceded during their past six games -- since the return to fitness of England goalkeeper Fraser Forster -- but Koeman remains wary of the threat from a rejuvenated Costa.
"Costa is one of the best strikers because he is always on the move and making it difficult for defenders,'' he said. "There is an emotional part in his character that makes it more difficult for himself, but as a defender you need to be full of attention for 90 minutes because if you are not he will punish you.
"Fraser Forster coming back has given everyone a boost," Koeman added. "But the whole team is working hard to keep clean sheets and it is difficult to score against us because we have good organisation.''