They were ranked 13th overall in preseason in PFF rating, Preseason is preseason, but what they did in preseason really is not indicative on how it will go. The LT is a big question mark, the other positions, if manned by the best 4 assuming everyone is healthy, have shown in preseason to be fine.
If Sow and Lowe are both out, the depth is weak, will be a challenge.
Bengals were middle of the road on sacks last year, worst in yards per attempt on defense for passing and overall a below average defense. Even though they are on the road the line should perform well, if they do not play well against the Bengals, and they have their starters, then we can say the issue is real.