This season, Jose Mourinho has two world-class goalkeepers at his disposal: Petr Cech and Thibaut Courtois. Only one can play at a time, so what one will be first choice?
Here, will we compare the goalkeepers.
Starting with Cech
Lets start with Petr Cech. After signing from French club Rennes in 2004, Cech has been the first choice goalkeeper, without any competition whatsoever.
Over 10 years as a Chelsea player, Cech has amassed more than 300 league appearances, making 161 clean sheets in the process, nine behind David James, who has kept the most. He has kept a club record 220 clean sheets for Chelsea in all competitions.
He is not short of club success either, winning three Premier League titles, four FA Cups, three Football League Cups, one UEFA Europa League and one UEFA Champions League during his decade with the club.
At Chelsea, Petr Cech has won the Premier League Golden Glove award three times. He won it for the first time in the 2004/05 season, Cech's first season in English football. Cech won it the second time in the 2009/10 season, and finally he was the joint-winner of the award in the 2013/14 season, along with Arsenal's Wojciech Szczesny.
Cech has the knowledge and history of the Premier League with him, which could be an advantage for the decision on the number one spot.
What about Courtois?
Moving onto Thibaut Courtois. Despite originally signing for Chelsea in 2011, Courtois is yet to make his league debut as a Chelsea player.
After signing with Chelsea, Courtois was loaned out to Atletico Madrid. He spent three years on loan at the Madrid-based club, making over 100 league appearances while at the side.
Despite only being 22 years old, Courtois recently celebrated an impressive feat; 100 professional clean sheets. A very good stat for a goalkeeper at his age.
On loan at Atletico, Courtois won many personal accolades. He won La Liga Zamora Trophy on two occasions in 2013 and 2014 respectively. Courtois also won La Liga Goalkeeper of the Year award in 2013.
Like Cech, Courtois has won many club trophies. On loan at Atletico, he helped his side to win one Copa del Rey, one UEFA Super Cup, one UEFA Europa League, and one La Liga title.
Both goalkeepers are highly talented and they will be both vying for the number one spot.
Who will it be: Cech or Courtois?