The 25-year-old midfielder has been on the reigning Premier League champions' radar for some time, after continuing to impress in Spain.
Citizens boss Roberto Mancini is keen to bring him to the Etihad Stadium in January, and now knows the exact amount of money it will take to make the move possible when the transfer window reopens.
Speaking to AS, Real Betis president Rafael Gordillo revealed that Benat - as he is most commonly known - might be on his way out of Seville.
"We want Benat to continue with us, but if someone pays the clause we can not do anything," he said.
Mancini was frustrated in his attempts to sign his key targets in the summer but following an underwhelming start to the season for Manchester City - which has seen them eliminated from the Champions League, as well as being six points off the pace in the Premier League title race - he is expected to plead for more support in the transfer market.