Edwards is having his right shoulder checked before Wednesday's game versus the Cardinals, Bobby Blanco of MASNSports.com reports.
The Nationals have Joe La Sorsa with the team in Washington in case they need to place Edwards on the injured list. The right-hander has appeared in 32 games with the Nationals with a 3.69 ERA and 1.52 WHIP over 31.2 innings despite a lackluster 24:17 K:BB.