Thibaut Courtois
Courtois has defended his team-mates amid mounting criticism. Getty Images

Chelsea goalkeeper Thibaut Courtois has launched an attack on critics of the squad's commitment this season amid a harrowing campaign at Stamford Bridge. Eight losses from 15 games have seen the Blues all-but relinquish their Premier League title, while Jose Mourinho's team is still on the precipice of exiting the Champions League.

Defeat to Porto, coupled with a win for Dynamo Kiev over Maccabi Tel Aviv, will see West Londoners crash out of the competition. A group stage exit – that could see the 2012 winners drop into the Europa League – will see the pressure ratchet up on Mourinho's already compromised position as manager.

Among the common themes of Chelsea' showings this season, after they romped to the title and the Capital One Cup last term, has been the underperformance of several of their key players. Eden Hazard, Diego Costa and Cesc Fabregas have all failed to recapture their best form, but Courtois says his teammates are not lacking in dedication.

"Who says we don't have the same commitment?" the 23-year-old said ahead of the game, according to the official Chelsea website. "Results don't say we are not committed to the manager. Sometimes we have been better than other teams and still lost, that doesn't say anything about our commitment, results are just not there. We are still confident in the manager, we are one team and we are trying to get out of it with him.

"Everybody's free to think what they want but we are trying to work the same way as we did last season, when we were champions and won the Capital One Cup. Results are not good and we are aware of that, we need to improve as a team. It's easy to say it's only the manager but every player, every member of the technical staff has to get better and then we will be near the top again. We have to keep working hard in training.

"We have to put in a good performance in front of our fans and win the game. Hopefully that will give us a boost ahead of our match against Leicester on Monday, that's another important one and hopefully we can get on a winning streak."

Mourinho believes he retains the backing of Chelsea owner Roman Abramovich despite a desperate season that continued with a 1-0 defeat to AFC Bournemouth. The results have come following the dismissal of team doctor Eva Carneiro – who is taking legal action against the club and the Portuguese boss, with Mourinho also accused of having fallen out with several first team players.

Courtois, however, believes that in each Chelsea lineup as many as eight players have failed to perform – a polar opposite to last season which saw the side dominate domestically. Though a draw will do against Porto to reach the last 16, the Belgium international says they will not rest on their laurels

"If you play just to draw you never know what can happen in the last minute," he added. "We will play to win. Every footballer wants to win their games and it will be same tomorrow. We want to give our fans a victory because this season we've lost too many games at home and it shouldn't be like that.

"All the players have to improve our level, we are a team but sometimes individually we haven't been at our best. If everybody gets to their top level we will start winning games. Sometimes in a season you have months when you are at a higher level. You might have eight players at a top level and three a bit down but this season maybe it's been the other way around and it's more difficult, but we are still the same players from last season."