Nicolas Otamendi is thought to have already agreed personal terms with Manchester City

Valencia have told Manchester City they want more money for Nicolas Otamendi's proposed transfer to go through, according to Sky Sports' Spanish football expert Guillem Balague.

Balague believes a deal had been in place for a fee of £28.4m plus France international Eliaquim Mangala being sent on loan to the Spanish team.

Mangala has impressed since the season started, however, and City boss Manuel Pellegrini has decided he wants to keep the 24-year-old in his squad.

With the terms of the agreement changing, Valencia are understood to have responded by saying they now want a higher fee for Argentina defender Otamendi.

The former Porto player - who moved to the Mestalla in February last year - has a release clause of £35.5m in his contract.

Otamendi is thought to be in Manchester having already agreed personal terms with City and is refusing to train or play for Valencia in a bid to force through a move to England.