Iowa State linebacker Caleb Bacon underwent surgery Sunday after suffering an injury to his lower left leg in the Cyclones’ season opener.Iowa State coach Matt Campbell said Monday that Bacon could “have the opportunity” to return later this year.Bacon sustained the injury in the first quarter of Saturday’s 21-3 win over North Dakota. A redshirt junior and former walk-on, Bacon had 60 tackles (6.5 for loss) and three sacks last season.