Kroldrup was a part of the Danish squad that managed to get a impressive away win against Portugal.
The Fiorentina defender said: “I return to Florence after ten days with my national team and even though I did not play, I worked a lot with my team-mates.
“In my role there is a good competition, considering that Laursen and Agger are amongst the best in the world in that role.
“I will train with the group in these days. There are many players who returned to the squad following the commitments with their respective national sides, but everyone is concentrated on the match against Napoli.”
He added: “At Naples we expect a very motivated team and with great individualities. We know that it will be a difficult game under the tactical and fighting aspect, but I know that we can contrast them with the right game organization.”