Eastham is set to leave Blackpool at the end of the season when his contract expires at Bloomfield Road.
Blackpool were hoping to secure Eastham on a new deal, but the player is keen to move on in search of regular first-team football.
The 22-year-old spent most of this season on loan at Bury, as well as spells at Fleetwood and Notts County, to continue his development.
Eastham was one of Bury's shining lights despite their relegation from League One and a host of sides have been keeping tabs on progress.
Crawley are thought to be long-term admirers of Eastham with Red Devils boss Richie Barker having worked with him during his time in charge of Bury, while MK Dons and Notts County are also weighing up moves for the powerful defender.