Courtois has been linked with a move to Real Madrid at the end of the season.
Real boss Zinedine Zidane is looking for a replacement for Keylor Navas, and has also been linked with a move for Manchester United star David De Gea.
The Blues are reportedly prepared to offer Courtois a new deal to ward off Madrid's interest.
Marcos Alonso is hopeful Chelsea star Thibaut Courtois won't join Real Madrid
And Alonso is desperate for his Chelsea team-mate to stay at Stamford Bridge.
"I really hope [Courtois does not join Real Madrid] because he is great goalkeeper and he is helping us every game," Alonso told Spanish radio station Onda Cero.
Alonso also spoke about Chelsea's push for the Premier League title.
The Blues are eight points clear at the top of the table with 13 games remaining.
Burnley 1-1 Chelsea: 10 key statistics from the match
Sun, February 12, 2017
Express Sport brings you 10 key statistics from Chelsea's 1-1 draw with Burnley at Turf Moor
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Express Sport brings you 10 key statistics from Chelsea's 1-1 draw with Burnley
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Marcos Alonso believes not playing in Europe has given Chelsea an advantage this season
"The team are playing very well," Alonso added.
"We have adapted very well to the idea of the coach and we hope to continue this way until the end of the season.
“We are training a lot and very well. The team has understood perfectly what the coach wants and we are proving that every weekend.
"It is clear that not playing Europe is an advantage over other teams but we are training very well, and I think that's the most important thing. That's what is allowing us to stay free of injuries and play with almost the same eleven every weekend."