Career
A product of local KuPS, Pennanen made his senior debut on 29 April 2007 at the age of 16 against VIFK. A month later, he was a starter against PK-35. During that season he managed to appear in 13 first-team matches. On February 2009 Pennanen signed a two-year contract with the Dutch team Football Club Twente along with teammate Tuomas Rannankari.
However after not making a single appearance for the Football Club Twente"s first-team, Pennanen left the Dutch champions during the winter 2011 and signed with TPS. He signed with RoPS before the 2014 season.