A youth product of Real Madrid, where he primarily served as a backup, Adan has spent most of his career with Betis. He has also played for Atlético Madrid, for whom he signed in 2018, and has accumulated a total of 129 La Liga appearances across these clubs.
Esteghlal, under the management of Portuguese coach Ricardo Sá Pinto, is seeking a new goalkeeper to replace Hossein Hosseini.
The Iranian goalkeeper has been linked with Tractor, prompting the club to look for a suitable replacement.