Tiatia names his side to face Perpignan, who have won all three home games and lost all three in the Top 14, on Thursday, but is poised to be without several props.
Tight-head Rob Hunt suffered an elbow injury in the defeat by Ospreys and is still being assessed amid fears of a lengthy lay-off.
His replacement, Chris Coleman, suffered a head injury and is going through return-to-play protocols.
Wales prop Dillon Lewis is back in the selection mix with Owain James, the other specialist option at tight-head, although loose-heads Rhodri and Wyn Jones have previously played there.
Argentina loose-head Rodrigo Martinez went off in the early stages against Ospreys, but it is hoped his shoulder injury is not serious.