Mertens has now revealed that a number of clubs were chasing his signature, but the 30-year-old is adamant that there was never any doubt about where his future lay.
"Discussions on my contract were always going to happen, there was no real pressure," he told the media on international duty.
"The Premier League is the best competition for me, but I am happy at Napoli.
"It is possible that Barca were interested, but I have not had any direct contact. After a season like that, I am super happy at my club. I didn't want to leave.
"There was also interest from Chelsea and other clubs, but, in my head, there was never any intention to change clubs."
"It was a shame not to finish as top scorer in Serie A," he added. "Next season, I'll stay as an attacker."