Sanchez admitted: "We need to get through this third-round tie in the competition.
"If we do that we go to Chelsea in the league on Saturday in good form and you never know what can happen.
"We have a lot of good quality in the side now but at this stage of the season there is a lot we still have to iron out.
"If we can get the defensive problems out of our system we are good enough going forward to really make an impact.
"Our last two home games (both 3-3 draws) sum us up right now. We are entertaining, we score for fun and seem to also concede goals for fun. We go into leads, we give them up, we fall behind and then we find the tenacity to come back.
"My reckoning is that we are about 80% there for what I want, but it is the other 20% we must get right. Some aspects of our game are great - others are not very good at all.
"It is my job to get it sorted out and I'm confident I will. Then we'll show the quality we have."