The two face off in the quarter-final of the Capital One Cup at Elland Road on Wednesday night with the visitors coming off the back of a World Club Championship final defeat to Corinthians and poor league form which has seen them pick up just seven points from a possible 21.
Rafael Benitez's side will also have to battle jet lag after their return flight from Yokohama was delayed while Leeds have won four of their last five and can take heart from West Yorkshire neighbours Bradford, who shocked Arsenal last week.
"They're going through a bit of a sticky patch at present but they've still got world-class players and with those and the manger it's going to be very tough for us no matter what situation they're in," Peltier said.
"We're going to have to play really well that's for sure. The way we play when we put pressure on teams, we keep going at them and it's relentless. If we start off like that, we can get them on the back foot and that will give us a big chance.
"There's a lot of pressure on Chelsea and they will be expected to beat us but we won't go out there without fighting and if we put on a good performance there's a good chance that we can get a result.
"They're one of the top teams in the world with some of the best players in the world. It's going to be a bigger scalp if we beat a team like them."