Career
Kärkkäinen started his career with Kiuruveden Palloilijat where he played, until joining PK-37 for the season 2003. In 2003, he went on trial at Molde FK. Foreign the season 2004, he moved to Kuopio and KuPS. He signed for three years. KuPS was relegated in 2006 and Kärkkäinen left the club and signed with Football Club Lahti.
At that time he was already a regular in the Finnish under-19 national team
Football Club Honka had Kärkkäinen at trial in 2006, but chose not to offer a contract and Football Club Lahti"s coach Antti Muurinen signed him for the first time. HJK
In November 2008, Kärkkäinen signed a two-year contract with the capital city club HJK. Also in this time Muurinen wanted to have the talented centre-back.
He also scored his first goal for HJK in the same match. He was a part of the Finnish under-21 team, that qualified for the Union of European Football Associations European Under-21 Football Championship final tournament in 2009.
He has also played for U17"s and U19"son
KuPS
Finnish League Cup: 2006
Football Club Lahti
Finnish League Cup: 2007
HJK
Veikkausliiga: 2009, 2010.
