Scott Hogan is expected to move from Brentford to West Ham this week, according to Sky sources.
Sources close to the striker believe the deal is being affected by Hammers playmaker Dimitri Payet's future, but are still confident Hogan will move within 48 hours.
Hogan has scored 14 goals in the Championship for the Bees this season but the 24-year-old was not part of the team who were beaten 2-1 at Wigan on Saturday.
Brentford manager Dean Smith told the club website after Saturday's match: "Scott Hogan has trained all week with us but had a tight hamstring yesterday.
"It is not the kid's fault, he wants to play football, but he doesn't want to risk getting injured.
"I fully understand that but I think, if he has a tight hamstring in February, he plays."
Meanwhile, Payet continues to be linked with a move from West Ham to his former club Marseille, although the French side said last week they were resigned to not completing a deal during this transfer window.