The Spaniard is out of contract at the end of the season and free to talk to other clubs.
However, Alonso Pena said that his son is a professional and is fully concentrated on the Trotters' push for promotion back to the Premier League.
"Yes, Fiorentina are very, very close to Marcos," he told Tuttomercatoweb. "We were in Florence for the first time in December, to speak with the Viola.
"But now Marcos wants to finish this season quietly with Bolton, trying to do his best professional job to bring the club into the Premier League."
Alonso, 22, arrived at the Reebok Stadium from Real Madrid in 2010.