The Argentine defender is being tracked by the Gunners and Barcelona this season.
And he said, "Apparently I'm doing something right.
"I read about it and accepted it for notification. I feel good at Ajax, I think and live in the now."
He told ELF Voetbal: "Betis was the most serious of all clubs. The contract was ready. But I had already been in Spain. I wanted something completely different. Experiencing a different culture, learning a different language."