Skysports.com understands West Ham have had a bid rejected by Southampton for centre-back Aaron Martin.
Premier League strugglers the Hammers have already moved to strengthen their frontline in this month's transfer window, bringing in strikers Demba Ba from German club Hoffenheim and Robbie Kean on loan from Tottenham.
And now manager Avram Grant has seemingly turned his attention to the club's defence, reportedly making an offer for young stopper Martin.
However, League One side the Saints are thought to have spurned the approach as they concentrate on their promotion push this term.
Martin, who spent time on loan at non-league side Salisbury City last year, has made three League One appearances for the Saints this season, as well as two cup outings.