Interim Chelsea manager Guus Hiddink insisted captain John Terry cannot be replaced as the out-of-contract defender prepares to return from injury against Tottenham.
Terry, who is unlikely to be offered a new contract at the end of the season, has been sidelined since March due to Achilles and hamstring injuries but will make his comeback in Monday's hosting of Premier League high-flyers Tottenham.
Chelsea have struggled in the absence of the 35-year-old, eliminated from the FA Cup and Champions League, not that Hiddink is surprised.
"Of course we have missed him. What a club likes is to have competition for that position. It will make the team stronger," Hiddink said in quotes published by the Mirror.
"He will react if there's competition - 'Don't touch my spot'.
"Would we have done better with him in the team? Yes, that is the problem. I don't like to complain, but at the time we didn't get through in the FA Cup and Champions League, we had a lack of players in central defence.
"Kurt Zouma and John, so we had to reshuffle, which makes the team a bit insecure. John was almost unapproachable when he got this setback, which shows a big desire to play."