The Spanish league leaders needed a late goal from Lionel Messi to beat Athletic Bilbao 2-1 at home on Sunday, but it was an uncharacteristically nervous display at the end of a week in which they seemed to have lost some of their spark.
Barca were held to a 1-1 draw at Sporting Gijon the previous weekend, and they followed that by letting slip a one-goal lead to lose 2-1 to Arsenal in a Champions League last-16 first leg last Wednesday.
"Physically we are fine, but when you come off the back of a 16-match run of league wins and don't win, the alarm bells seem to start," Pique told Barcelona TV.
"This (to draw and lose a game) can happen, so to get back to winning ways was important for the team and for the fans, for them to see we are the same team we were a week ago.
"Barca have always been one of those teams that have struggled to win evenly balanced games, and many points and leagues have been lost in these matches.
"On Sunday, we showed we have changed our mentality and that we now know how to win those types of games as well."
Barca are five points clear of Real Madrid at the top of La Liga and face Arsenal in their Champions League second leg on March 8.
