Manchester City will not let Eliaquim Mangala leave on loan in this transfer window, sources told ESPN FC.
Valencia were reportedly keen to take the France international to the Mestalla for the season if they could sell Argentina centre-back Nicolas Otamendi to City.
But the Premier League leaders are determined to keep Mangala, who is keen to remain at the Etihad Stadium.
The 24-year-old endured a difficult first season in England following his £42 million move from Porto in August 2014.
But he has begun the current campaign in the team, partnering captain Vincent Kompany in the centre of defence and helping City keep back-to-back clean sheets in the 3-0 wins over West Bromwich Albion and Chelsea.
And City are not willing to let the most expensive defender in Premier League history leave at a time when he appears to be producing his best form for the club.
Mangala sent a Tweet on Sunday evening which suggested he wants to stay at City, saying: "I am a Citizen."
2 games, 2 victories, 2 clean sheet! I like it ! I am a Citizen. I never give up... #Motivated #NeverGiveUp #MCFC pic.twitter.com/vNBjaeWuAI
- Eliaquim Mangala (@Elia22Mangala) August 16, 2015
City's situation with Valencia is complicated by the fact that the La Liga club are yet to pay all of the €30 million they owe for Alvaro Negredo.
The Spain international striker returned to his home country last season on loan, but with the guarantee of a permanent move in 2015.