Messi marked his 300th La Liga appearance with a hat-trick as Barca recorded an 11th straight victory in all competitions - Neymar and Luis Suarez also on target, the latter with a stunning overhead kick.
Luis Enrique made eight changes from Barca's Copa del Rey success over Villarreal on Wednesday but the coach explained Messi was never likely to be rested.
"I'm not going to rest him while he is enjoying himself so much," the 44-year-old explained. "When we play against teams who close up at the back, we need to create space and elaborate chances quickly.
"Leo's ability to do that is key for us.
"The objective we set ourselves was to build an ample squad with quality and we’re very satisfied with the results.
"In the first half we lacked balance but later, in the second half, we were very good. Everyone wants to play their part in this and this victory really reinforces our confidence."
Barca's 11th consecutive win broke a previous record set by Pep Guardiola, although Luis Enrique dismissed its importance.
"I didn't know that we'd beaten that figure. To be honest, I'm not really interested," he added.
"We can look back and evaluate what it means at the end of the season. If it means we win silverware, then great."
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