Complex sentence: Starting his career in FC Viikingit before moving to HJK in the Finnish top league in 2003, he debuted in 2003, his 2005 season ended badly with a serious injury in the middle of the season.
Split into simpler sentences: Starting his career in FC Viikingit before moving to HJK in the Finnish top league in 2003, he debuted in 2003. His 2005 season ended badly with a serious injury in the middle of the season.