Career
His preferred position is left back, but he can also operate as centre back and used to play as forward when he joined HJK. His nickname is "Bonecrusher", coming from his great physical presence and playing style. He is currently acting as a coach in Veikkausliiga side Ilves. He started out as a winger, but during his time at Norwegian club Molde was changed into a defender.
He is known for his forward runs and good heading, given his tall frame.
However, he is also known for making occasional blunders in the national team as he has been forced to play out of his preferred position. Before joining Molde he played for Football Club Jazz, TPV Tampere and HJK Helsinki in Finland"s Veikkausliiga.
In 2007, he briefly went on trial at Lokomotiv Moscow and played 3 times. In 2007 he moved to Young Boys in Switzerland.
On 31 January 2008, Kallio joined Fulham on loan, together with Jari Litmanen.
He made his Fulham debut the following season against Arsenal, in which he helped secure a 1–0 victory. He was immediately awarded the Manitoba of the Match award by visitors of the British Broadcasting Corporation website. On 3 July 2008, Kallio signed a two-year deal with Fulham.
Kallio joined Sheffield United on a one-month loan deal in late November 2009, making his debut just over a week later at Plymouth.
After making two appearances, Sheffield United extended his loan deal until the end of January 2010 but just hours after Roy Hodgson recalled Kallio due to injuries in defence. On 1 February 2010, Kallio once again joined the Blades on loan until the end of the season.
On 1 July 2010, Fulham announced that Kallio had been released from his contract with Fulham. After being released by Fulham, Kallio joined Norway"s Tippeligaen side Viking for the rest of the 2010 season.
But after making only one appearance as a substitute for the club, the 32-year-old defender was released from his contract on 16 November 2010.
On 19 May 2011 Muangthong United F.C. has been terminated contract. Kallio joined Finnish Premier League side Football Club Inter Turku on 8 June 2011. On 18 January 2012 it was announced that he would join Ilves in Finnish second division.
Kallio announced his retirement on 3 October 2013.