LSU quarterback Myles Brennan sustained a left arm injury that will require surgery, the school announced on Monday.
Sources told ESPN that Brennan is believed to have a broken arm. A timeline for his return is unclear.
Brennan began last season as the starter, throwing 11 touchdowns in three games before an abdominal injury ended his season.
A fourth-year junior, Brennan said earlier this offseason that he was feeling 100% again. He was expected to compete for the starting job with Max Johnson.
Johnson, the son of former NFL quarterback Brad Johnson, came on late last season as a freshman, leading LSU to a 2-0 record.