I'm wondering if we won't see Eathyn move back inside. He did a nice job there his freshman year when we lacked depth at NT and only moved to the DE position when big guys like Travis Tuiloma and Loni Fangupo joined the team.
Although Tialavea played NT before his mission, he lost a ton of weight when he sat out due to injury before leaving for the mission field and he's still slimmed down upon his return. At 6'3" and 266 lbs he's pretty undersized to be very effective as a NT.