Ernesto Valverde's side will go into the tournament off the back of a disappointing 2-2 draw with Espanyol in the Catalan derby.
"We did the most difficult thing, which was to come back [from a goal down] at a rival's stadium," Suarez said.
"I think we lost two points today.
"There are things to improve, whether you draw, lose or win.
"You have to evaluate what happened and then improve.
"We knew that it was going to be a difficult game, but now we've got great days coming up, days to try to win a trophy.
"We have to improve looking to the Supercopa."