Liverpool and Arsenal are battling for Werder Bremen defender Per Mertesacker this month.
Gunners boss Arsene Wenger has confirmed he could make a defensive signing in January - and Mertesacker is top of his shortlist.
Liverpool are also chasing the Germany international, who is available from Werder after their Champions League elimination.
Director of Football strategy for Liverpool, Damien Comolli, is thought to have watched the player last month and taken an interest in a potential January signing despite interest from their Premier League rivals the Gunners.
Werder are hoping to sell at £10 million.
