The Australia international parted company with the Hammers at the end of last season, with his deal at Upton Park having reached its conclusion.
He has since been linked with a host of clubs, including Turkish giants Galatasaray and Premier League outfits Sunderland and Hull, as well as his former employers Blackburn.
Neill is yet to find employment though, and domestic action across Europe is now well underway.
The 31-year-old full-back is understood to prefer a move away from England, as he is keen to steer clear of imminent income tax hikes.
Primera Liga outfit Atletico Madrid are now the favourites to secure his services, with Neill admitting he is close to making a decision on his future.
"I'm in talks with a club outside England. It's a change from what I've been used to," said the former Millwall man.
"A decision will take a lot of courage so that's why I've taken my time."