Delabar, who pitched for the nearby Florence (Ky.) Freedom in independent ball before making it to the Major Leagues in 2011, auditioned for the Reds by throwing off a mound for the club in Indianapolis on Saturday before their 13-6 win over the Pirates.
In eight games this spring for Toronto, Delabar had a 2.35 ERA. He has not been the same pitcher since a breakout All-Star 2013 season when he had a 3.22 ERA and a 12.6 strikeouts-per-nine innings ratio over 55 appearances
In 2015, Delabar recorded a 5.22 ERA in 31 games for the Blue Jays while averaging 9.2 strikeouts per nine innings.
Cincinnati has yet to set its 25-man roster ahead of Monday's opener vs. the Phillies (4:10 p.m. ET). The club should provide some more clarity on Sunday, when it's scheduled to hold a workout at Great American Ball Park.
Mark Sheldon is a reporter for MLB.com. Read his blog, Mark My Word, follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.