NASCAR is likely to make a baseline concussion test mandatory for all drivers in 2014.
Steve O'Donnell, NASCAR's senior vice president of racing operations, says officials have also urged all drivers to get an ImPACT test before this season.
The test is used by many professional sports leagues, including the NFL, to assess concussions and determine when an injured athlete can safely return to play. O'Donnell says NASCAR will "likely" make the test mandatory next season.
Four-time Cup champion Jeff Gordon voluntarily took the test and says all drivers should complete one even if it's not mandatory.
Last season, Dale Earnhardt Jr. missed two races during the Chase for the Sprint Cup championship with a concussion.