The Giants’ five-man starting offensive line made it intact through training camp and the entire preseason, but there was a starter on the sideline during the first day of heavy preparation for the Cowboys.

Mike Remmers, the starting right tackle, did not practice Wednesday, and he was listed on the injury report as not participating because of illness and an issue with his back.

Remmers, 30, had back surgery this offseason, which makes this situation worth watching. He held up through the summer, and there are indications the Giants do not believe this is a worrisome situation. Back issues, though, can be tricky.

Coach Pat Shurmur, prior to practice, did not mention Remmers would not be working. Shurmur did seem to speculate there is nothing serious with Remmers when he said: “As we get going here, I’ll let the injury report speak for itself. I’m not trying to be cryptic about it. If there’s a big injury or something, we’ll talk about it. But if there’s a guy that’s going to end up being out there on Sunday, I won’t mess with it too much.’’

There is no proven depth behind Remmers, or behind left tackle Nate Solder. Chad Slade, a second-year player from Auburn, figures to be next in line if Remmers is unavailable. Slade, 27, played in five games, starting three of them, for the Bengals in 2017.