Diafra Sakho will seek specialist help as he strives to recover from a back injury.

The Senegalese striker has stayed behind in London while the rest of the Hammers squad who have travelled to the USA for their pre-season tour, which kicks off with a meeting with MLS club Seattle Sounders on Tuesday.

Sakho complained of illness and a sore back prior to the trip and will now employ the assistance of a specialist in a bid to solve the problem as soon as possible.

The 26-year-old continues to be linked with a £12million summer move to Sunderland.