SAF tried to keep Pogba, yet felt that he wasn't showing enough in the reserves to be a regular starter...he identified that Pogba needed to work harder on his game. 'He tried everything to keep Pogba', except playing him, so basically he felt that Pogba was a good talent, but not mature enough to play for the 1st team.
This is a man that will give any half decent academy player a chance in the team, if they show the right attitude they will get games. Pogba was very good as a youth player, so when a manager like SAF doesn't give you games, then he thinks you are not committed to playing under him.