The Hammers, who travel to Stamford Bridge tomorrow, beat Chelsea 3-1 at home in December.
The West Ham boss told the team's website: "It would be our first double of the year, we've had many other opportunities that we've blown. It would be an absolutely unbelievable result for us to win at Stamford Bridge and do the double over Chelsea in the same season.
"It's one of those things that happens rarely, for you to be able to beat a top side home and away. It's a great incentive for the lads to go out there and achieve that on Sunday.
"We should have enough to try and stay in the game as long as possible. We obviously want to score first if we can, but if we can't, as long as we keep the game tight, then inevitably they must tire based on the workload they have had and you can find some gaps and spaces."
West Ham are 12th in the Premier League table ahead of this weekend's games.