West Ham United have made an approach for Panathinaikos defender Bryce Moon, skysports.com understands.
The South African full-back has been mooted as a long-term target for the Hammers, with Gianfranco Zola a known admirer of the 22-year-old.
Skysports.com understands West Ham have lodged an offer worth £1.5million but the Greek giants are holding out for £2million.
Moon intimated that he knew of West Ham's interest in the January transfer window but a move to England failed to materialise.
Lucas Neill's departure has left the Hammers short defensively and Moon is thought to be a key contender to fill the void.
With their initial offer having been rejected, the Premier League club must now weigh up their options before returning to Panathinaikos.