Cesc Fabregas-Diego Costa
Chelsea duo Cesc Fabregas and Diego Costa have been key four Mourinho this season.Getty

Chelsea goalkeeper Thibaut Courtois believes Jose Mourinho's side are currently stronger than the one which last season faced Paris Saint German due to the summer additions of both Diego Costa and Cesc Fabregas.

Following a campaign without any silverware, the Chelsea boss made a big overhaul in the summer by signing the Spanish duo, as well as Filipe Luis, Didier Drogba and Loic Remy, while Courtois himself and Kurt Zouma returned to west London after their respective loans at Atletico Madrid and Saint Ettiene.

The Blues beat PSG in the quarter-final of the Champions League last season after Demba Ba scored a late goal at Stamford Bridge to knock out the Ligue 1 side with a 2-0 victory – following a 3-1 defeat away.

However, Chelsea were later eliminated in the semi-finals by Courtois, who was then playing at Atletico Madrid. Questioned by French radio RMC whether Chelsea have improved from last season ahead of their Champions League last 16 second leg trip – after a 1-1 draw in the first leg – he said: "Last year I played against Chelsea and I beat them with Atletico"

"Chelsea were already strong but this season, with the arrivals of Diego Costa and Fabregas, the team have progressed. Technically, maybe we are stronger than last year. We have a very good team."

Apart from Costa and Fabregas, Courtois has also lavished praise on Eden Hazard and Kurt Zouma, claiming the duo are in the process of becoming the best players in their positions.

"Hazard is still not at the level of Messi and Ronaldo, who are head and shoulders above all the other players. But Eden has the potential to get there. He's only 24 years old. He can still improve. He has the potential to be a future Ballon d'Or. But as long as Messi and Ronaldo play like that, scoring 30 goals in 30 matches, it won't be easy."

While speaking about Zouma, he added: "He has a lot of talent. He is strong. He is good with the head and plays well with the feet too. He will improve and I think that he can become into one of the best defenders in the world if he continues the progress because he is already a very good player."