In February, Roman Reigns returned to WWE after taking a four-month break to fight leukemia. According to Tom Colohue of Sportskeeda, Reigns has not yet returned “full time” in WWE, which may explain why Reigns has not been reinstated in the main events of the shows.

After returning, Roman Reigns was involved several times with Drew McIntyre and Shane McMahon and more recently collaborated with The Undertaker to face the two at Extreme Rules. Since Roman is not yet 100%, WWE put him in tag team match to protect him somehow.

From a #WWE source:



"Roman still isn't back full time completely. He wanted to be back straight away but WWE are happy to have him protected in tag matches or short matches spread out and big media appearances." — Tom Colohue (@Colohue) July 20, 2019

Roman hasn’t returned full-time yet. He wanted to return immediately but WWE is happy to have protected him in couple matches or short matches and in big media appearances.”