Olli Maatta, the Pittsburgh Penguins' 21-year-old defenceman, is set to join Finland's military on April 18, according to Finnish reporter Juha Hiitela.

If Pittsburgh makes the playoffs, the date will be postponed.

Seth Rorabaugh of the Pittsburgh Post-Gazette wrote about Finnish players serving in the military back in 2013.

Because of Maatta's NHL career, serving six consecutive months could be troublesome. He's expected to break up his service into a few summers in order to complete it.

Hiitela also mentioned some prominent NHL players that still have outstanding service obligations: Alexander Barkov, Rasmus Ristolainen, Teuvo Teravainen and Kasperi Kapanen still need to serve. 

Teemu Selanne, Saku Koivu, Kimmo Timonen and Tuukka Rask all completed their service before reaching the NHL, but Hiitela noted that with players reaching the league at younger ages, the mandatory service time could become a bigger issue.