Miettinen was a three-time All-American at Division II power Franklin Pierce and later worked under former Franklin Pierce coach Mark Krikorian as a team manager and later assistant at Florida State, where Krikorian is the head coach.
Miettinen, who made 26 international appearances as a goalkeeper for Finland and starred for HJK, is currently in her first head coaching job at Finnish club PK-35.
PK-35 is tied with Sport for first place with two games to play in the Veikkausliiga, Finland's top league.
Sky Blue's revolving door began when Ian Sawyers, husband of Julie Foudy, was fired in May. Assistant Kelly Lindsey took over but abruptly resigned late in the regular season.
U.S. national team captain Christie Rampone was then named player-coach and guided Sky Blue FC to the playoffs, which it won with a three-game sweep. Afterward, Rampone revealed she was pregnant. She is due in March and is not expected to play again until June.