Assuming he's fit, Marler to start on Saturday. I'd start Lang and Mulchrone, Smith & DC on the bench.
While I'd like to see Bothma start, Chis minor has played well & I can't see him being dropped. Robbo if fit is one of the first names on the teamsheet, and I don't think we would have a back row of Bothma, Chis & Robbo. There's too much "sameness" in that combination.
Centres I'm happy with whoever Gussie picks (and that's the official spelling from the program of Gustard's nickname, so I'm staying with it!). Walker I think needs to drop to the bench, & have Ibitoye startimg. Walker's looked off his game so far. Ibitoye offers the same speed, but more weight in both attack & defence.