The Redskins are out of the playoffs, but Kirk Cousins could still get a Super Bowl ring this year -- if he buys the one Mark Rypien won back in 1988 ... 'cause it's officially on the auction block.
TMZ Sports has learned ... Rypien's championship ring from Super Bowl XXII is up for grabs via Goldin Auctions -- starting bid is $15,000.
Of course, Rypien didn't play a single down in that game -- when Washington beat Denver 42-10 -- 'cause he was only a rookie back then ... playing behind Doug Williams and Jay Schroeder.
Goldin Auctions tells us Rypien sold the ring back in 2013 -- and the current owner has decided the time is right to put it back on the market.
We're told the ring is expected to fetch around $50k.
Don't feel bad for Rypien -- he went on to lead the Redskins to a victory in Super Bowl XXVI ... and even took home the MVP trophy.
We're guessing he hung on to that ring.