WWE originally had plans for a local enhancement talent to play the role of Roman Reigns' tag team partner against Shane McMahon and Drew McIntyre in this week's RAW main event, according to PWInsider. Plans were changed as there was a pitch over the course of the day for Cedric Alexander to play the role.
It was speculated that the appearance could lead to more RAW TV time for Cedric, as he hasn't been used much since coming to the red brand from WWE 205 Live in the 2019 Superstar Shakeup. It was noted that this is the plan as there is scheduled to be a follow-up to Cedric teaming with Reigns on Monday's post-Extreme Rules edition of RAW.
As noted, the role of the Prudential Center janitor Gary "The GOAT" Garbutt, that led to Cedric wrestling under the mask, was played by Kosha Irby, who worked for WWE for 7 years as their regional director for live events in the Memphis area. We have details on Irby and his background at this link.