Old school jerseys

I keep seeing people using older jerseys like the Kelley green eagles or the 2010’s jets uniforms. How can I get these or is it just luck based on the field pass uniform packs

There have been some uniform rewards in the field passes, and there was a uniform pack (not sure if it's still there). You can also buy them still on the AH, but good luck finding the one you want.

The third TOTW challenge each week has an old school uni, just find the team you want