The University of Iowa has suspended linemen Alaric Jackson and Cedrick Lattimore for the Hawkeyes’ season opener, upping the number of starters that will miss the Sept. 1 game against Northern Illinois for team violations to four, ESPN reports.

The nature of the violations were unspecified, but the school said that neither player is involved in a legal matter. Team violations can include poor academic performance, attendance, timeliness, behavior, effort and engagement. The infractions reportedly took place in the spring.

Jackson, a sophomore, started 12 games last season at left tackle for the Hawkeyes, earning first-team freshman All-America honors from the Football Writers Association of America and All-Big Ten academic honors. Lattimore, a junior defensive tackle, started the first six games last season and recorded 15 tackles, 1.5 for loss.

“As a coach one of the most important decisions is to hold student-athletes accountable,” Head coach Kirk Ferentz said in a prepared statement. “It is painful for the players and the team to impose a suspension, but we have high standards and there is an expectation all players abide by our rules.”

Iowa announced last month that starting defensive lineman Brady Reiff and starting offensive lineman Tristan Wirfs would be suspended for the opener for alcohol-related violations during the summer.