The Tigers moved eight points clear of the relegation zone with a 2-0 win over West Bromwich Albion on Saturday, and can distance themselves further when they face the Hammers at Upton Park.
Long told the club's official website: "Saturday was a big three points for us and it has opened up the gap a little bit more. Most results went for us and we can go to West Ham on Wednesday on a high. This is a big week with two tough away games and I'm sure West Ham will be looking for the three points at home.
"We're going to have to be on form to get something from these games but we're definitely good enough to go and get a couple of results and we could be a long way towards being safe by next Saturday."
Hull are 12th in the Premier League on 33 points after 30 games this season.