EUGENE, Ore. — A pair of Ohio State starting offensive linemen exited Saturday’s top-three showdown at Oregon in the first half of a 32-31 defeat. Redshirt sophomore right guard Tegra Tshabola came back. Redshirt junior left tackle Josh Simmons didn’t. Tshabola went down on a 53-yard run by running back TreVeyon Henderson late in the first quarter. Then, on a 3rd-and-9 during the following Buckeyes offensive series in the second quarter, Simmons took a tumble while blocking Oregon outside linebacker Matayo Uiagalelei. Simmons appeared to grab his left knee after hitting the turf of Autzen Stad…