Edwards signed a minor-league contract with the Cubs on Thursday, per the MLB transaction log.
Edwards returned to the Cubs on an NRI deal in January, but he opted out of that contract March 23. He'll rejoin Chicago and start out with Triple-A Iowa. As a member of the Nationals last season, Edwards posted a 3.69 ERA, 1.52 WHIP and 24:17 K:BB over 31.2 innings.