Cucurella was voted Brighton's player of the season last termManchester City target Marc Cucurella has handed in a transfer request at Brighton.
The Seagulls have already rejected one bid from City for the defender and are understood to be holding out for a £50m fee for the former Barcelona player.
The 24-year-old left-back joined Brighton from Getafe last summer.
He has been identified by City manager Pep Guardiola as a replacement for Oleksandr Zinchenko, who left City to join Arsenal this summer.
Cucurella is understood to feel Brighton's asking price is unrealistic.
A Barcelona academy graduate, he has one senior cap for Spain and played for the under-23 side that won silver at the 2020 Tokyo Olympic Games.
Asked about the defender at a news conference for the Community Shield with Liverpool on Saturday at the King Power Stadium, Guardiola said: "He is a Brighton player. I cannot say anything."
Pressed further on his desire to sign a left-sided defender, the City boss added: "If it is possible, yes.
"If not, we stay with what we have. We have enough players who can play there, Joao [Cancelo] can play there. Nathan [Ake]."
Guardiola also confirmed that centre-back Aymeric Laporte is expected to be sidelined until September after knee surgery.
"Laporte is injured," said Guardiola. "He had knee surgery after last season and playing the last two or three games with an important injury. He made an incredible effort.
"So far he is doing really well, but you have to be careful with a knee. I think August will be out, September I think maybe he will start to be with us."
