Chelsea are going great guns in the English Premier League having won their opening four matches, while Schalke are depleted by injuries to several key stars.
However, Nigeria international Obasi told africanFootball.com, “I think it is going to be a tough game for us because Chelsea are in good form and my team are battling injuries.
“I respect Chelsea as a team, they have good players and a good manager like Schalke 04, and I think we can manage ourselves for victory.”
Obasi said he is banking on the experience of his teammates in this competition.
“We have players who have played in this competition before and we are as ready as Chelsea are,” he said.
“No big deal if we upset Chelsea, every game can’t go their way all the time and they must be humble enough on the pitch.
“In the Champions League, upsets happen, there is no underdog and that’s why a team like Schalke 04 will always be there. We are top team.”
Obasi was not available for Nigeria two Africa Cup of Nations qualifiers this month against Congo and South Africa even though he was called up.
Meanwhile, Schalke 04 will be without captain Benedikt Howedes in the clash with Chelsea FC.
The 2014 World Cup winner checked into a local hospital on Monday for an assessment on a troublesome groin injury, and did not travel to London with the rest of Jens Keller’s squad on Tuesday, undergoing further tests instead.
The Royal Blues, who are still searching for their first competitive win of the season, are already without fellow centre-backs Joel Matip (groin) and Felipe Santana (muscular), as well as Atsuto Uchida, Sead Kolasinac, Leon Goretzka, Fabian Giefer and Jefferson Farfan.