Graham Potter, who was appointed in January, is under pressure to turn things around. The team's current position in 18th place is a cause for concern.
The club is considering O'Neil, a former midfielder who played for West Ham from 2011 to 2013. During his time at the club, he made 56 appearances and scored three goals.
O'Neil's availability is seen as an attractive option for West Ham, as it would not require a transfer fee from another club.
