Loffreda said: "We are improving in each game, but we need to be at a very high level next Saturday.
"The team was really solid throughout the game against Sale. We put in a very good performance and I'm satisfied."
Ahead 10-3 at the break, Leicester pulled clear in the second half.
Dan Hipkiss cross to open up a 17-3 lead and, after Luke McAlister's effort reduced the deficit to nine points, Andy Goode kicked a penalty and Tom Varndell raced in from the halfway line to put the game beyond the visitors.
Tom Croft grabbed the bonus point for Leicester in injury time and Loffreda admitted the three second-half tries were the result of a change in tactics.
Torrential rain fell in the first half and Loffreda said: "Instead of kicking the ball, we have to move it, but we had to be sure than we controlled possession and we did that."
Loffreda expects to have All Black centre Aaron Mauger available for the game in Toulouse and said: "We didn't want to rush him into the team.
"I think he will be available next week."
Cardiff's win over Bath meant Sale could not have qualified for the semi-finals even if they had won at Leicester.
Head coach Philippe Saint-Andre saw his side ship 15 points in the last 13 minutes and said: "We were playing catch-up rugby, took some risks and they punished us.
"I thought we could get the game back to three or four points (after McAlister's try), but there was an interception and that was game over.
"We matched them for much of the game and I was pleased with the forwards, but the last few minutes were disappointing."