Interim manager Guus Hiddink said Chelsea are in a “transitional period” after Paris St-Germain knocked them out at the Champions League last-16 stage for the second successive season.
The Blues face not being in Europe’s elite competition next season for the first time in the Roman Abramovich era after Wednesday’s 4-2 aggregate defeat.
They are currently 10th in the Premier League, 10 points off the top four.
“Chelsea must consider their short-term future,” said Hiddink.
A year ago Chelsea were also out of the Champions League, but top of the Premier League on 63 points from 27 games as they cruised to a third title under Jose Mourinho.
The Portuguese has now been sacked and the Blues are 23 points worse off than on this date last year – despite having played two more games.
They last missed out on the Champions League in the 2002-03 season, after finishing sixth under current Leicester boss Claudio Ranieri.
“Chelsea are now in a transitional period and they now have to see how to go on to try to regain the lost terrain where they used to be,” said Hiddink, who will leave his post in May.
“It is difficult to get into fourth in the Premier League, but we knew that and we tried to do our first job, which was to get out of the relegation zone.”
