FC Dynamo players have not joined the Armed Forces of Ukraine. The image is of members from Gonor, a Ukrainian far-right group.
This claim is inaccurate. The men in the photo are members of a Ukrainian far-right group known as "Gonor", which means honor. The Italian fact checking organization, Facta, reported that Serhii Sterneko, a Ukrainian right-wing activist and member of Gonor, first shared the image on his Facebook page on February 24, when Russia invaded Ukraine. Gonor also shared the photo on its Instagram account, @gonor.group. According to Vice, the right-wing group describes itself as a "civic activist movement."
FC Dynamo Kyiv's social media manager, Bogdan Ilyuk, confirmed to Reuters that the team's players did not appear in the photo.