The European champions hold a 3-1 advantage ahead of the second leg at the Luzhniki Stadium, but Moses says they will not be distracted by Sunday's FA Cup semi-final against Manchester City at Wembley.
"We'll focus on the game," said the Nigeria international. "It's the Europa League, it's a massive game for us. We just want to put the City game behind us at the moment. That doesn't come until Sunday.
"Rubin Kazan are a great team, so we're here to do our best. We're very focused.
"It's not going to be an easy test for us, but we're looking forward to it. If we can score an early goal that would be great for us.
"Hopefully we'll do our best to try to win the game and get into the semi-final."
Chelsea manager Rafa Benitez added: "We have a lot of respect for Rubin Kazan. We know that it's a good team.
"All my players know how important this competition is and they will be really pleased if we go through and will go to the final and if we can win the final."