The prop suffered a back injury in November that forced him to miss the entirety of the NatWest 6 Nations but is named in a strong side by head coach Richard Cockerill to travel to Ireland.
Blair Kinghorn returns at full-back following his impressive introduction to international rugby in recent weeks in the only change in the back line from an impressive 12-6 win over Munster last week.
Nathan Fowles is back at scrum-half for the side that will be captained by Grant Gilchrist, who played an important part for Gregor Townsend’s Scotland over the course of the Six Nations.
Simon Berghan will line up on the other side of the scrum to Marfo after starting on the bench last week as Cockerill’s side look to build on an impressive run of four successive wins, which has propelled them to third in Conference B of the Guinness PRO14.
Cockerill said: : “We’re taking steps in the right direction. We’re working as hard as we can.
“Last week against Munster, I just wanted the boys to go out there and play as well as they could. The effort was just unbelievable, it’s where we want to be.
“We know how tough an opponent Connacht are - especially at home, where conditions aren’t always brilliant. But, we’re going there full of confidence that we can get a positive result.”