, manager Arsene Wenger is desperate to sign a centre-half in the January transfer window and has earmarked Upson as the deal candidate.
Should the 29-year-old move to the Emirates, in what is being suggested will be a £12 million deal, it would mark a remarkable u-turn for the England defender.
Upson began his top-flight career at Arsenal before being sold to Birmingham in 2003 for just £3m.
Reports suggest that £5m-rated striker Nicklas Bendtner will be used as part exchange in the deal.
West Ham will be reluctant to part with Upson. They have already rejected £12m bids from Tottenham and Manchester City for Craig Bellamy and have made a point of saying that their prize assets - namely Upson, Bellamy and Scott Parker - are not for sale.
However, it has been suggested that Upson would welcome a return to the Gunners, who would provide him Champions League football and a regular shot at the Premier League title.
Meanwhile, former Arsenal striker Sylvain Wiltord is poised to join Marseille on a six-month loan from Stade Rennes.
Wiltord, 34, left Arsenal for Lyon back in 2004.