The Hammers have enjoyed a decent run of form of late, and after successive Premier League wins over Southampton and Liverpool during the festive period, Slaven Bilic's men then beat Wolverhampton Wanderers 1-0 in the FA Cup at Upton Park on Saturday.
Bilic may not have a lot of money to spend this month having landed the likes of Angelo Ogbonna, Pedro Obiang and Dimitri Payet over the summer, but it seems that the Croatian is still keen on improving his squad if possible.
The Mirror report that West Ham are looking to beat Italian side Fiorentina to the signing of Benfica defender Lisandro Lopez, and are set for a meeting in Lisbon on Monday over a possible deal.
The 26-year-old centre back - not to be confused with his namesake who impressed as a striker with Porto and Lyon - has largely struggled for first-team football at Benfica ever since his 2013 move from Arsenal de Sarandi, and spent a whole season on loan at Getafe upon his arrival in Portugal.
This term, Lopez has played a little more under new manager Rui Vitoria, but a January exit could still be on the cards for the four-cap Argentina international, if West Ham get their way.
West Ham's history with Argentinian players is somewhat mixed; they've had major successes with Manuel Lanzini and Carlos Tevez, and some indifferent moves with Javier Mascherano and Mauro Zarate - but that doesn't seem to be putting them off as they allegedly move for Lopez.
Signing another centre back could suggest that Bilic sees James Tomkins' long-term future as a right back, meaning Lopez would compete with Winston Reid, Angelo Ogbonna and James Collins in the heart of defence, if West Ham can fend off Fiorentina.