Unlike the left outside linebacker job, the starting spot at right tackle has not already basically been decided. It's believed that Jason Fox has a slight edge on Corey Hilliard in the position battle, but the gap between them is not big enough for Jim Schwartz to come out and declare a leader or anything like that.
Through the first two preseason games, Fox and Hilliard have played a pretty equal number of offensive snaps. Fox has been on the field for 55 snaps on offense, while Hilliard has gotten 61. For Fox, he has been involved in pass blocking on at least 40 of his snaps, according to Pro Football Focus, and he is performing at a pretty high level so far. From PFF:
Right Tackle Jason Fox is looking like he should be a starter in Detroit. Over 40 pass blocking snaps Fox has yet to give up a pressure.
It'd obviously be nice to see how many pressures Hilliard has given up so far, but that number wasn't included. Even so, it's probably safe to assume that if Hilliard was perfect in pass protection as well, it would have been mentioned.
In any case, this is another piece of evidence that suggests Fox will ultimately become the Detroit Lions' starting right tackle. What happens on Thursday in the Lions' "dress rehearsal" against the New England Patriots could help solidify that if Fox keeps playing like he has so far in the preseason.