Chipper Jones' baseball skills have apparently deteriorated over the years ... 'cause the MLB legend just embarrassingly fumbled an attempt at catching a foul ball Monday.
The former Braves star's gaffe just went down in the second inning of Atlanta's playoff tilt with the Brewers ... when Milwaukee 2nd baseman Luis Urias hit a pop fly toward the ex-3rd baseman, who was sitting just a few rows behind home plate.
The ball was hit sky high ... and despite camping underneath it and having a Hall of Fame baseball resume -- Chipper muffed the grab!