Prior to Winston Reid's injury, West Ham were already looking at bringing in a central defender before the transfer window closes. And manager Manuel Pellegrini's desire for such an acquisition will only hasten with Reid now expected to be out for up to three months. 

Newcastle captain Jamaal Lascelles appears to be Pellegrini's primary target with Sky Sports reporting of a £20m bid from West Ham being turned down.

Lascelles' role in helping Newcastle stay up in the Premier League last season and his overall standing at the club means the Magpies are unlikely to change their stance on not wanting to sell the 24-year-old.

Therefore, Pellegrini will have to try elsewhere and one option that may be accessible and can help improve the team's options at centre-back is Manchester United's £16.2m-rated (via Transfermarkt) Chris Smalling.

While Smalling is a name that is likely to underwhelm West Ham supporters, especially considering how well the transfer window has gone for them so far, the 28-year-old has improved massively under the tutelage of Jose Mourinho.

Smalling's standard of defending has gone up a notch and he is no longer as error prone as he was in the earlier stages of his Manchester United career.

The England international also looks better aerially and is starting to come up with some big goals from set pieces.

Mourinho already has Eric Bailly, Phil Jones, Marcos Rojo and Victor Lindelof to pick from, while Manchester United's interest in Toby Alderweireld has been well-documented, making room for a potential Smalling exit.