NHL players signing overseas during the lockout must go through the process of getting their International Transfer Card approved, and that process can take up to seven days.
Filpulla becomes the third NHLer to sign in Finland, joining fellow-countryman Jussi Jokinen of the Carolina Hurricanes, who signed with Karpat, and San Jose Sharks defenseman Jason Demers, who also signed with Karpat.
In 81 games with the Red Wings last season, Filpulla enjoyed a career-year, registering 23 goals and 43 assists for 66 points, along with a plus-18 rating.
Meanwhile, Filpulla's teammate, Pavel Datysuk, is expected to sign with Dynamo Moscow of the KHL.