Andre Villas-Boas' side sit top of Group K after two matches and already boast a four-point cushion over Thursday's opponents Sheriff.
Despite hailing from the capital of the breakaway state of Transnistria, Sheriff have won the Moldovan top flight 11 times this century.
They are on course to take it again this season but are ranked by some bookmakers at 10/1 to win their home clash with Tottenham.
"We are looking forward towards this match," Rusnac said ahead of the sold-out clash at Stadionul Sheriff.
"Everyone is looking forward to the game, including our players, coaching staff and management.
"Tomorrow we play against one of the best teams in Europe, who occupy a leading position in one of the best championships in Europe.
"We understand that they are a team of a high European level and we understand that they are favourites not only in our group but in the whole tournament.
"Nevertheless, we are going to fight tomorrow. We prepared very seriously for this game.
"For every player of our team, it is a big opportunity to show just what we can do.
"Tomorrow, we are positive that all of our players will do their best to achieve a good result for us. We respect our opponents, but we have no fear and will fight tomorrow."
Rusnac is assisted at Sheriff by Juan Ferrando, who as a fitness trainer worked with Cesc Fabregas and Robin van Persie at north London rivals Arsenal.
"I should thank UEFA for pairing Sheriff with Tottenham," the Spaniard told mundodeportivo.com.
"Yes, at Arsenal I enjoyed working with these derbies. I like stronger rivals. I also would have liked to see Valencia, Betis and Sevilla in my group.
"My challenge is that the Sheriff be made known and become a classic European team. What a Tottenham player takes a week is equivalent to our annual budget."