When Thibaut Courtois joined Real Madrid, Chelsea avoided losing one of football’s best goalkeepers for nothing.

The Belgian had one year left on his contract and would have been available for nothing in 2019, just like Pedro, who signed a new deal at the club to keep him there until 2020.

have a number of other players entering the final year of their contract, though, and here, talkSPORT.com looks at four key men the Blues could decide to cash in on during this transfer window.

There are actually eight players whose contracts expire in 2019, but Rob Green, Wily Caballero and Lucas Piazon won’t, in all likelihood, play much. Mateo Kovacic, meanwhile, is on loan at Stamford Bridge for the season.

1. Gary Cahill

What a steal Cahill has turned out to be. The Blues signed him from Bolton in 2012 for £7million and it was thought the club would cash in on the 32-year-old during the transfer window.

“The majority of Chelsea fans have been unbelievable to me, but there is maybe an element of five per cent always thinking ‘get the next best thing in’ or ‘move him on’. I can feel that in a certain percentage,”

he told the Telegraph in May. He still played 27 times last season and the majority of fans will be sad to see him leave when he finally does head for the exit.

2. Olivier Giroud

Chelsea paid £18m for him in January and the striker signed an 18-month deal, so it appears he was always going to be a short term option.

When Giroud moved across London from Arsenal it was because he wasn’t getting enough minutes on the pitch and the World Cup winner was recently linked with Marseille in his native France. It’s a move he never considered, however.

“No, I am happy here at Chelsea,” he said.

“I just arrived a few months ago and am just starting to settle well. I still have one year [of my contract] to go with Chelsea, plus maybe another one. I’m going to discuss that with the club at the right time. There is no rush.”

Giroud’s signing did appear to be a short term solution

3. Cesc Fabregas

Not many midfielders are better than him in possession of the ball, are they? He’s still better than Ross Barkley, Danny Drinkwater and Tiemoue Bakayoko, isn’t he?

And he has only just turned 31, so you would imagine there will be plenty of takers, especially if he is available for nothing in 2019.

Cesc Fabregas could leave Chelsea

4. David Luiz

He rarely played for the club during the second part of last season. A troublesome knee and Andreas Christensen didn’t help and it was believed he was on his way out.

That may have happened if Antonio Conte had kept his job as manager, but he appears to be back in favour under new boss Maurizio Sarri, a man Luiz said he is loving life under.

“I very much enjoy his attitude when I am working with him,” Sarri said of the Brazilian.

“He is also a very good player and a very good defender. David is very good at building up action from our defence with the way he plays. David has a big future here. He will be very useful for us but not just on the pitch, he is also important in the dressing room.”