You must have AT LEAST 7 players on the line of scrimmage. You are welcome to have more if you like! Kizer redirected Jones into the tight end spot to help with pass protection. That gave the Irish 8 on the line of scrimmage. Like another poster said, if Jones had gone downfield for a pass he would have been an ineligible man downfield because he was covered by Fuller on the line of scrimmage. Jones stayed in to block, so the play is perfectly fine.