The 21-year-old signed for Barnsley last week on a four-year deal from Danish top-tier side AC Horsens.
He is relatively unknown in this country, apart from within the Reds' thorough scouting network, but his career begin in the youth system and Brondby – one of Denmark's top clubs.
And he believes that will stand him in good stead.
“I played for 10 years in one of the biggest clubs in Denmark, so I had a good footballing school,” he said.
“I left Brondby to get some minutes and make sure I get plenty of games, which was important for me. I am now here, so it means it was good.”
Andersen – a centre-half – met his new team-mates for the first time on Monday as Daniel Stendel's side began pre-season training.
The move to South Yorkshire is a step into the unknown for him, but it will not take him long to get acquainted.
“I have no friends here, but I will make some, no problem,” he said,
“This is a feeling I have never had before, this is a good feeling and I am ready. The atmosphere is so good at the club, everyone I have met so far, they are smiling and happy.”
Monday's session was also the first time fellow new recruits Luke Thomas and Brad Collins met their new team-mates.