The circa 1937 Lou Gehrig game worn New York Yankees jersey recently sold for $870,000.

Heritage Auctions

WHAT: The pinstriped, game-worn flannel shirt donned by baseball great Lou Gehrig for the iconic image of the faintly smiling player mounted on a bronze plaque in Monument Park recently sold for a whopping $870,000 at Heritage Auctions in Dallas.

Part of a $10.7 million Heritage Auction platinum night sports sale, the jersey result cemented Gehrig as an all-time icon. Note the 4 on the back; it was the first number ever retired by a Major League franchise.

Gehrig's jersey was the second-highest selling lot in the sale. A Norman Rockwell painting of Major League Baseball umpires hit $1.68 million.

MORE: A major selling point for the jersey is that it was photo matched, down to a replaced button.

In 1937, used jerseys were repurposed for farm clubs, so the Yankees logo on the front was removed. Once the jersey was located and restored, a New York logo from another 1937 Yankee team jersey was placed in the original spot. Sleeves were usually shortened for farm club use; one has been restored with another from a same-period shirt. Heavy wear attests to the player's 40-some games for the team.

SMART COLLECTORS KNOW: An original version of the classic Monument Park photo brought $5,000 at Heritage in 2015.

HOT TIP: Red stitching with the player's name on the inner collar has faded, plus there is an anchor point for a "fat strap" (now gone) to keep the shirt tucked in.

BOTTOM LINE: Less than two years after Gehrig last wore this shirt as a Yankee, he retired due to the neurodegenerative condition ALS, now also known as Lou Gehrig's disease.