The Argentine now has 15 in 14 Serie A games after his double.
“The attitude we had in the first half was a bit of a problem, then my goal calmed Cagliari down a bit… They had a really good game," he told Mediaset Premium.
“We do our work, focus on our results and winning our games. The other teams know we are there, we're pressing them and will enjoy tonight as the Serie A leaders.
“We've been working well for a couple of years, doing great things and we can see the fruits of our labour. I try to make sure I am ready when the ball comes my way. I got another brace tonight and I'm enjoying my football."
There were reports this week that Real Madrid would be ready to activate the €110m release clause in his contract.
“The club talks about the release clause, but you all know how I feel. There's nothing to say."