Iowa has lost starting offensive linemen Brandon Scherff and Andrew Donnal to season-ending injuries.
Hawkeyes coach Kirk Ferentz says Scherff, a sophomore left tackle, broke a bone in his leg during Saturday night's 38-14 loss to Penn State.
Donnal, a sophomore right guard, hurt his right knee in the first half against the Nittany Lions.
Junior Nolan MacMillan will move into Scherff's starting spot at tackle for this weekend's game between the Hawkeyes (4-3, 2-1 Big Ten) and Northwestern (6-2, 2-2).
Redshirt freshman Austin Blythe will likely replace Donnal at guard.
The loss of Scherff and Donnal is a blow to an offense that has scored just 26 points in the past two weeks.