Lukaku is out of the game against his parent club.
Long told Absolute Radio's Rock 'N' Roll Football: "Yeah he's a big loss you know, he slotted into the team and last Saturday playing with the two of us front it felt really good together but we're lucky that we have different options to play with one or two up front and whatever the manager chooses you know we'll be used to it.
"Whether he just brings in Rosenburg or Fortuné or Odemwingie instead of Romer he'll change the formation totally. We'll wait and see. Yeah I'm sure he'll have us really prepared to play against a good Chelsea team."