West Bromwich Albion boss Tony Pulis has called on fans to out-sing their West Ham United rivals during their FA Cup tie.
West Ham have taken their full allocation of 5,500 for the match at the Hawthorns, with some 4,000 seats still vacant at this stage in the West Brom sections.
Pulis said: "The last thing we want to do is play a game at the Hawthorns where the away support make more noise than the home support.
"The club have done a deal on the game. Fingers crossed we need to get a full house and make it a real, real cup atmosphere. We need to sell another three or four thousand.
"In the context of the season the priority is to stay in the Premiership. But we also want to well in the Cup. We will be going flat out tomorrow as I'm sure Sam will.
"West Ham are bringing more than 5,000 supporters tomorrow. That's how important it is to that football club."